UNIVERSITY Self learning material Of Introduction to Computers

UNIVERSITY Self learning material Of Introduction to Computers

BHOJ (OPEN) UNIVERSITY

Self learning material

Of

Course – 7,Unit – 1

Introduction to Computers

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UNIT – 1 INTRODUCTION TO COMPUTER

1.1 Introduction

1.2 Fundamentals of Computer

1.2.1 What Is Computer

1.2.2 Uses of Computer

1.2.3 Necessity of Computer

1.2.4 Important Terminology: Input and Output Devices

1.2.5 Types of Computers

1.2.6 History of Computers

1.2.7 Free Open Source Software System

1.3 Computer Memory

1.4 Computer Language and Its Types

1.5 Operating System

1.5.1 Dos and Windows

1.5.2 Security and Antivirus

Let Us Sum Up (Summary)

Answers

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1.1 INTRODUCTION

Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, on your lap, or even in your pocket. Computers work through an interaction of hardware and software.

Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. The most important piece of hardware is a tiny rectangular chip inside your computer called the central processing unit (CPU), or microprocessor. It's the "brain" of your computer—the part that translates instructions and performs calculations. Hardware items such as your monitor, keyboard, mouse, printer, and other components are often called hardware devices, or devices.

Software refers to the instructions, or programs, that tell the hardware what to do. A wordprocessing program that you can use to write letters on your computer is a type of software. The operating system (OS) is software that manages your computer and the devices connected to it.

Windows is a well-known operating system.

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1.2 FUNDAMENTALS OF COMPUTER

Learning Objective :-

After studying this sub unit you would be able to – i. Define computer ii. Explain uses of computer iii. Explain the necessity of computer iv. Understand the input and the output devices v. Explain the types of computer vi. Describe the history of computers vii. Explain the free open source software systems

1.2.1 WHAT IS COMPUTER

A computer is an electronic device. It has the ability to store, retrieve and process data. In simplest form, a computer takes information (or inputs), processes it according to a set of instructions (a program), and gives back a result (or output). In this respect, it is very similar to a calculator, but obviously somewhat more complex.

The term computer is derived from the Latin term ‗computare‘, this means to calculate.

Computer can not do anything without a Program.

Let‘s know more

Charles Babbage is called the "Grand Father" of the computer.

The First mechanical computer designed by Charles Babbage was called Analytical Engine.

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Four Functions about computer are:

Input (Data):

Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc.

Process:

Process is the operation of data as per given instruction. It is totally internal process of the computer system.

Output:

Output is the processed data given by computer after data processing. Output is also called as

Result. We can save these results in the storage devices for the future use.

Program is a set of instructions which enables the computer to perform specified task

1.1.2 USES OF COMPUTER

Computers in Education –

Computers are used in school for teaching.

Computers are used for mathematical calculations.

Students can do their work by using computer.

One revolution in education is the advent of distance learning.

Computers provide better study moods.

Computer in Science –

Computers are used in scientific research to solve mathematical problems.

Helps scientists to understand the world around us.

Scientists can enter results and data into a computer.

Allow scientists to review information easily.

Computer in Health and Medicine –

Patients monitoring and record keeping.

Helps doctor in controlling operation theatre machine.

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Helps in medical diagnosis of the patient.

Hospital administration.

Help doctor with more advanced scanning equipment.

Computer in Business –

Computer allows businesses to keep detailed records.

Computers can be used to prepare detailed budgets and corporate forecasts.

It allows businesses to easily prepare dynamic marketing documents.

An important use of computers in business is running technical software.

Computer plays a vital role in advertising. Every advertisement is fully done with a computer.

Check the credit status of customers, and transfer funds automatically.

Computer in Defence –

Computers help in launching of missiles.

Keeping records of criminal.

Helps in constructing weapon and controlling their function.

Used in planes and tanks to target the enemy.

Establishes a communication link between the soldiers and commanders through satellite.

Modern radar system.

Computer in Home –

In playing games.

Music collection.

Write important documents and print them.

Computers can play a role in home security.

Use of computers in the home is for entertainment.

Computer in entertainment –

Used for making cartoon movies and animation films.

Computer in photo editing

Used for making drawings.

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Computers in banks –

Used in bank for storing information about different account holders.

Help in keeping the record of the cash.

Giving all kinds of information regarding any account in the bank.

Automatic teller machine.

Computer in office-

Computers can help managers keep track of the financial status of the company on a yearly, monthly or even day-to-day basis

.

Keep track of data about customers, products, demographics and other information important to the business.

Offices use computers for common purposes such as email and document creation

Computer in railway station and airport –

Gives information about ticket reservations and bookings.

Information regarding the arrival and departure time of trains and aeroplane.

Helps in keeping records of passenger.

Connects pilot with service station.

Computers are crucial to an airport's air traffic control services.

Computer in designing –

Fashion designers can use computers to construct patterns, design clothing, and create collections.

Adobe Photoshop and In Design are used to create marketing materials.

Computers help in designing buildings, houses etc.

Computer in travel and tourism –

Most new cars uses computer chip to control the engine.

Keep record of tourist.

Information about visit able sites

Government

use computer for planning, control and law enforcement activities such as

Travel, Tourism etc.

Computer in weather forecasting –

Weather stations

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Humidity measurement

Metrological studies

Computer in sports –

Computers also allow sports professionals to store a large amount of video footage in one place.

Computers have aided in the design of safety equipment in sports such as football helmets to shoes to mouth guards

Statistics are an important part of sports. computers can be used in sports in order to Keep track of the data.

Sports media outlets use computers everyday in their jobs.

1.2.3 NECESSITY OF COMPUTER

The computer is one of the most brilliant gifts of science. Today the computer plays a very important role in the life of each and every individual whether the individual is student, small businessmen or a large company. The computer has proved a friend and servant of science, technology and industry. Most offices, shops, factories and industries use computers. The

Internet on a computer is a storehouse of information. The computer is a boon to all. The most that any field has gained from the invention of the computers is the business field because of it‘s nature.

It‘s necessary to have a computer in school because computers are the new way to educate everyone, children are being taught to operate computers so that in the future everyone has knowledge of basic computing. Computers have gained importance as they have increased the productivity and efficiency of work done. Large amounts of data in the personal lives as well as in businesses and industrial sectors are stored on computers. Computers have also brought a revolution in the field of medicine. Not only clinics and hospitals can store data, the doctors can also make use of the computer to scan patients‘ bodies and even perform surgeries that would have been quite complex and dangerous to do so without the finesse provided by the computers.

Computers has help out a lot, in our daily lives where many of us can't live without one, by using computers and going on the internet, we can find any information on a person we want, like black history month, why go on the Library, when you could look up in computer as you can use

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the internet to look up current evens from around the world without being in that country. By using computers we can check up on the weather, before we go to work or school. So by checking the weather we already know if it's going to Rain or Snow or it's could be sunny. Then there contracting other family members, where many of us use our computers to text our family to see how there going, when member of you family is so far away living in a difference state or country.

By using our computers to shop on the internet we can find the product we are looking for, without going inside the retail store to look for it, only to find out it's sold out. Since, computers appear in our life, they are not only tools for working, studying but also entertainment also. By shopping on the internet it saves some a lot of trouble from looking for something that is not there. Computer is the backbone of information technology whose major application lies in internet. Internet has some very useful applications in our day to day life. The computer gives us many benefits. Eventually, computers come into every family and effectively influence our usual life. Thus computer has become an indispensable part of our daily life.

1.2.4 IMPORTANT TERMINOLOGY: INPUT AND OUTPUT DEVICES

Some devices are used to input information, while others are used to output information from the computers.

INPUT DEVICES –

An input device is anything that puts information inside the computer such as Keyboard, Mouse,

Scanner, Microphone etc.

Keyboard

The keyboard allows the entry of textual information. It consists of a set of keys mounted on a board as shown in fig 1.1

Alphanumeric Keypad - It consists of keys for English alphabets, 0 to 9 numbers, and special characters like + - / * ( ) etc.

Function Keys - There are twelve function keys labeled F1, F2, F3… F12. The functions assigned to these keys differ from one software package to another. These keys are also user programmable keys.

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Special-function Keys - These keys have special functions assigned to them and can be used only for those specific purposes. Some special function keys are enter, spacebar, backspace, delete, insert, shift, caps lock etc

Numeric Keypad - Numeric keypad is located on the right side of the keyboard and consists of keys having numbers (0 to 9) and mathematical operators (+ − * /) defined on them. This keypad is provided to support quick entry for numeric data.

Cursor Movement Keys - These are arrow keys and are used to move the cursor in the direction indicated by the arrow (up, down, left, right).

Fig 1.1 Computer keyboard

Mouse

Mouse allows the selection of a point on the screen by moving a screen cursor to the point and pressing a mouse button as shown in fig 1.2 (a) and (b)

Fig 1.2 (a) Mouse

Mouse Actions -

Left Click - Used to select an item.

Double Click - Used to start a program or open a file.

Right Click - Usually used to display a set of commands.

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Drag and Drop - It allows you to select and move an item from one location to another.

To achieve this place the cursor over an item on the screen, click the left mouse button and while holding the button down move the cursor to where you want to place the item, and then release it.

Fig 1.2 (b) mouse pointer

Scanner –

Scanner is an input device used for direct data entry from the source document into the computer system. It converts the document image into digital form so that it can be fed into the computer as shown in fig 1.3

Fig 1.3 scanner

Microphone –

A microphone is used to record sound (usually through a sound card input or circuitry built into the motherboard). The sound is digitized i.e. turned into numbers that represent the original analog sound waves and stored in the computer to later processing and playback.

Fig 1.4 microphone

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OUTPUT DEVICES –

An input device is anything that display information such as Monitors, Printers, Audio Output

Devices.

Monitor

Monitor is a Cathode Ray Tube device which can display text and graphics. The monitor is associated with a keyboard for manual input of characters and displays the information as it is keyed in as shown in fig 1.5

Fig 1.5 monitor

Printer

Printers are used to produce paper (commonly known as hardcopy) output. Based on the technology used, they can be classified as Impact or Non-impact printers shown in fig 1.6

Impact printers use the typewriting printing mechanism wherein a hammer strikes the paper through a ribbon in order to produce output. Dot-matrix and Character printers fall under this category.

Non-impact printers do not touch the paper while printing. They use chemical, heat or electrical signals to etch the symbols on paper. Inkjet, Desk jet, Laser, Thermal printers fall under this category of printers

Fig 1.6 inkjet printer and laser printer

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Audio Output Devices –

The Audio output is the ability of the computer to output sound. Two components are needed:

Sound card – Plays contents of digitized recordings

Speakers – Attached to sound card

These devices are used to produce sound from the computer system. The soundcard is a card installed in the tower case of the computer. Its role is to convert the signal coming out of the computer to a format that can be reproduced by the external speakers.

Fig 1.7 speaker

LCD projector -

A Liquid Crystal Display (LCD) projector uses its own light source to project what is displayed on the computer on a wall or projection screen.

1.2.5 TYPES OF COMPUTERS

There are three different types of computers based on the principles of operation.

Computer

Analog

Super Computers

Mainframe

Computers

Digital

Hybrid

Mini Computers

Micro Computers

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Analog Computer

Analog Computer is a device that works on continuous range of values. The output given by the analog computers is approximate since it deals with quantities that vary continuously such as voltage, pressure, temperature, speed etc.

Digital Computers

A digital computer operates on digital data such as numbers. It uses binary number system in which there are only two digits 0 and 1. Each one is called a bit.

The digital computer is designed using digital circuits in which there are two levels for an input or output signal. These two levels are known as logic 0 and logic 1. Digital Computers can give more accurate and faster results.

Digital computer is well suited for solving complex problems in engineering and technology.

Hence digital computers have an increasing use in the field of design, research and data processing.

Based on the purpose, Digital computers can be further classified as,

General Purpose Computers

Special Purpose Computers

Special purpose computer is one that is built for a specific application. General purpose computers are used for any type of applications. They can store different programs and do the jobs as per the instructions specified on those programs. Most of the computers that we see today are general purpose computers.

There are four different types of computers based on the performance and capacity. The four types are

1. Super Computers –

The most powerful computers in terms of performance and data processing are the supercomputers. These are specialized and task specific computers used by large organizations.

The supercomputers are very expensive and very large in size. It can be accommodated in large

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air-conditioned rooms, some super computers can span an entire building. These computers are used for research and exploration purposes, like NASA uses supercomputers for launching space shuttles, controlling them and for space exploration purpose.

Let‘s know more

In 1964, Seymour Cray designed the first Supercomputer

"CDC

6600" .

Popular Supercomputers

IBM‘s Sequoia, in United States

Fujitsu‘s K Computer in Japan

IBM‘s Mira in United States

IBM‘s SuperMUC in Germany

NUDT Tianhe-1A in China

As of July 2009, the IBM Roadrunner, located at Los Alamos National Laboratory, is the fastest super computer in the world.

2. Mainframe computers -

Mainframe is a very large in size and an expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. Mainframe executes many programs concurrently.

Mainframes support many simultaneous programs execution.

They are used in banking, airlines and railways etc for their applications.

Popular Mainframe computers

Fujitsu‘s ICL VME

Hitachi‘s Z800

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3. Minicomputers –

A minicomputer is a multi-processing system capable of supporting from up to 250 users simultaneously. Minicomputers are also called as ―Midrange Computers‖. These are small machines and can be accommodated on a disk. It is a midsize computer.

Minicomputers are used by small businesses & firms. These computers are not designed for a single user. Individual departments of a large company or organizations use Mini-computers for specific purposes. For example, a production department can use Mini-computers for monitoring certain production process.

Popular Minicomputers

K-202

Texas Instrument TI-990

SDS-92

IBM Midrange computers

4. Microcomputers ( personal computers ) -

The invention of microprocessor (single chip CPU) gave birth to the much cheaper micro computers. The micro-computers are widely used & the fastest growing computers. These computers are the cheapest among the other three types of computers. The Micro-computers are specially designed for general usage like entertainment, education and work purposes. Well known manufacturers of Micro-computer are Dell, Apple, Samsung, Sony & Toshiba.

Because PCs were so much smaller than mainframe computers, they were called 'microcomputers' for a while

They are further classified into :

Desktop Computers - Desktop computers are the most popular computer systems. These desktop computers are also known as personal computers or simply PCs. They are usually easier to use and more affordable. They are normally intended for individual users for many other application.

Laptop / Notebook Computers - Laptop computers are portable computers. They are lightweight computers with a thin screen. They are also called as notebook computers

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because of their small size. They can operate on batteries and hence are very popular with travelers .The screen folds down onto the keyboard when not in use

Handheld Computers - Handheld computers or Personal Digital Assistants (PDAs) are pen-based and also battery-powered. They are small and can be carried anywhere. They use a pen like stylus and accept handwritten input directly on the screen. They are not as powerful as desktops or laptops but they are used for scheduling appointments, storing addresses and playing games. They have touch screens which we use with a finger or a stylus.

Palmtop Computer - A palmtop computer is similar to a laptop computer, but smaller.

It's small enough to fit in the palm of your hand (hence the name!) Palmtops are usually not very powerful and have a very small keyboard. Also a touch screen or tiny joystick is used. Palmtops are extremely portable, but the small keyboard and screen make the devices tiring to use for long periods.

Tablet computer – Like laptops, but with a touch-screen , sometimes entirely replacing the physical keyboard. It accepts the handwriting. Tablet computers are even more portable than laptops.

Hybrid Computers

A hybrid computer combines the desirable features of analog and digital computers. It is mostly used for automatic operations of complicated physical processes and machines. Now-a-days analog-to-digital and digital-to-analog converters are used for transforming the data into suitable form for either type of computation.

For example, in hospital‘s ICU, analog devices might measure the patient temperature, blood pressure and other vital signs

1.2.6 HISTORY OF COMPUTERS

The computer as we know it today had its beginning with a 19th century English mathematics professor name Charles Babbage. He designed the Analytical Engine and it was this design that the basic framework of the computers of today are based on.

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Computers can be classified into five generations. Each generation lasted for a certain period of time and each gave us either a new and improved computer or an improvement to the existing computer.

First Generation (1940-1955) Vacuum Tubes

The first computers used vacuum tubes for circuitry and magnetic drums for memory , and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.

First generation computers relied on machine language , the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.

The UNIVAC and ENIAC computers are examples of first-generation computing devices. In

1946 the first general– purpose digital computer, the Electronic Numerical Integrator and

Computer (ENIAC) was built. It is said that this computer weighed 30 tons, and had 18,000 vacuum tubes which was used for processing. When this computer was turned on for the first time lights dim in sections of Philadelphia. Computers of this generation could only perform single task, and they had no operating system.

The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census

Bureau in 1951.

Second Generation (1956-1963) Transistors

Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s.

The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.

Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.

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Second-generation computers moved from cryptic binary machine language to symbolic

or

assembly languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN . These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

The first computers of this generation were developed for the atomic energy industry.

Third Generation (1964-1970) Integrated Circuits

The development of the integrated circuit was the hallmark of the third generation of computers.

Transistors were miniaturized and placed on silicon chips , called semiconductors which drastically increased the speed and efficiency of computers. With this invention computers became smaller, more powerful and more reliable.

Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system , which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

Let‘s know more

An

integrated circuit (IC)

is a small electronic device made out of a semiconductor material. The first integrated circuit was developed in the

1950s by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild

Semiconductor.

Fourth Generation (1971-Present) Microprocessors

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.

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In1980 Microsoft Disk Operating System (MS-Dos) was born and in 1981 IBM introduced its first computer for the home user. Three years later in 1984 Apple introduced the Macintosh and the 90s gave us Windows operating system.

Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.

As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs , the mouse and handheld devices.

Fifth Generation (Present and Beyond) Artificial Intelligence

The "fifth generation" of computers defined by the Japanese government in 1980 when they unveiled an optimistic ten-year plan to produce the next generation of computers. Fifth generation computing devices, based on artificial intelligence , are still in development, though there are some applications, such as voice recognition , that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization such as capable of performing tasks in similar ways to humans, are capable of learning, and are capable of interacting with humans in natural language and preferably using both speech input (speech recognition) and speech output (speech synthesis).

As a result of the various improvements to the development of the computer we have seen the computer being used in all areas of life. It is a very useful tool that will continue to experience new development as time passes.

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1.2.7 FREE OPEN SOURCE SOFTWARE SYSTEM

Free and open-source software (FOSS) is computer software that can be classified as both free software and open source software . FOSS programs are those that have licenses that allow users to freely run the program for any purpose, modify the program as they want, and also to freely distribute copies of either the original version or their own modified version. That is, anyone is freely licensed to use, copy, study, and change the software in any way and the source code is openly shared so that people are encouraged to voluntarily improve the design of the software.

Definition of FOSS

Free software" is a matter of liberty, not price. To understand the concept, you should think of "free" as in "free speech" not as in "free beer"

- Richard Stallman (FSF)

Definition of FOSS -

The word "free" in our name does not refer to price; it refers to freedom.

First, the freedom to copy a program and redistribute it to your neighbors, so that they can use it as well as you.

Second, the freedom to change a program, so that you can control it instead of it controlling you; for this, the source code must be made available to you

- Free Software Foundation (FSF), Feb 1986

All the software on the Live CD and the DVD are Free and Open Source software, with a few notable exceptions (Flash, Opera, Acrobat Reader and more) in the non-oss repositories . When we talk about free software we refer to freedom not a price.

Free open-source operating systems such as Linux and Open BSD are widely utilized today, powering millions of servers , desktops , smart phones (e.g. Android ) and other devices.

Free Software –

Free software is defined by the offering of 4 basic freedoms:

The freedom to run the program, for any purpose

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The freedom to study how the program works, and adapt it to your needs

The freedom to redistribute copies, so you can help your neighbor

The freedom to improve the program, and release your improvements to the public, so that the whole community benefits

Open Source –

It emphasize the technical and economical benefits of open source code and open development, and care little or nothing at all about the ethical aspects. However there is very little software acknowledged by the Open Source Initiative that is not also Free Software, hence the term

FOSS (Free and Open Source Software) is often used.

Benefits of FOSS

Decreasing software costs

Increasing security and stability (especially in regards to malware )

Protecting privacy

Giving users more control over their own hardware.

Better quality control

Examples of Free and Open Source Software

Operating systems –

Linux - Operating system kernel

Ubuntu - Linux distribution with full compliment of software for everyday use.

Google Chrome OS - Lightweight operating system based around the web browser

Android smart-phone operating system - by Google / Open Handset Alliance

Symbian smart-phone operating system - by Nokia

MeeGo smart-phone operating system - joint venture between Intel and Nokia

BSD - Operating system

Darwin - The core of Apple's Mac OS X , operating system

GNOME - desktop environment for Linux (and Unix)

KDE -desktop environment for Linux (and Unix)

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Xfce - lightweight desktop environment for Linux (and Unix)

Programming Languages –

C, C++, Mono, PHP, Python, Perl, Ruby, TcL

Check your progress – 1 a)

A computer has the ability to ……………., …………… and …………….. data.

b)

Program is a set of ……………….

c)

An ……………. device is puts information inside the computer.

d)

There are ………………. function keys.

e)

…………… device converts the document image into digital form.

f)

…………. Computer is a device that works on continuous range of values and

……………computer operates on digital data.

g) ……………………. Is regarded as the father of computer.

h)

First generation computers relied on ……………………

1.3 COMPUTER MEMORY

Learning Objective :-

After studying this sub unit you would be able to – i. Define computer memory ii. Explain types of computer memory

The computer memory is a temporary storage area . It holds the data and instructions that the

Central Processing Unit ( CPU ) needs. Before a program can be run, the program is loaded from some storage medium into the memory. This allows the CPU direct access to the program.

Memory is a need for any computer .

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The CPU calls instructions and data from the computer's memory. Because the same computer performs different tasks at different times, the memory is erasable—much like audio cassette .

But there are some programs and instructions which the computer needs. It does not matter what function you are performing. These programs often are permanently recorded in the memory. So

RAM primary memory

ROM memory

Punching

Devices

Magneti c Tape

Floppy

Disk secondary memory

Optical

Discs

(CD/DVD)

Flash

Drives

Hard Disk

Drives

SRAM DRAM

PROM EPROM EEPROM they cannot be destroyed. As a result, the computer's memory usually consists of two parts:

PRIMARY MEMORY –

Primary Memory (also called main memory) is used for immediate access of data by the processor. While primary memory storage demonstrates faster processing ability, it is costly and hence is not largely used for data storage. Most computer systems around the world use primary memory only for bootstrapping and related purposes, and use secondary memory devices for personal data storage purpose.

Primary Memory can be divided into two types - Random Access Memory (RAM) and Read

Only Memory (ROM).

RAM retains its contents as long as the power supply is on. A RAM chip is used as primary memory in most computers today. However, older computers (in the '80s) used ROM devices

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(floppy disks, magnetic tapes, paper clips or punches; but more prominently floppy disks) as primary memory mechanisms.

RAM –

RAM stands for Random Access Memory also referred to as main memory, primary memory or system memory. RAM refers to read and write memory that is you can both write data into

RAM and read data from RAM. RAM is volatile, which means that it requires a steady flow of electricity to maintain its contents. As soon as the power is turned off, whatever data was in

RAM is lost.

A computer's RAM is the memory used to store data and programs on a temporary basis. The amount of RAM directly affects a computer‘s performance. The more RAM a computer has, the more programs and documents it can open without slowing the system down.

Current PC computers have anywhere from 256 MB of RAM or 256 million bytes of memory a program can use, to as much as 4 GB of RAM. Mac computers generally have between 128 and

512 MB of RAM.

There are primarily two forms of RAM: Static RAM (SRAM) and Dynamic RAM (DRAM).

Static RAM: The most expensive of the lot, SRAM uses bistable latching circuitry to store one bit each, and hence is faster than its counterpart. Its high price prevents it from being widely used in everyday computing machines, but many modern machines use

SRAM as the processor's cache register.

Dynamic RAM: Widely used in modern computers as primary memory, DRAM is slower than SRAM, but is inexpensive due to its one transistor-one capacitor paired assembly of memory storage.

ROM –

ROM stands for Read Only Memory.

ROM is a type of "built-in" memory that is data can only be accessed and read by the user, not overwritten, upgraded or modified .

The system programs stored on a ROM device could never be altered and hence, stayed secure for use. ROM is nonvolatile which means it keeps its contents even if the power is cut off. In addition, ROMs are

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used extensively in calculators and peripheral devices such as laser printers , whose fonts are often stored in ROMs.

PROM (programmable read-only memory): A PROM is a memory chip on which you can store a program . But once the PROM has been used, you cannot wipe it clean and can not use it to store something else.

EPROM (erasable programmable read-only memory): An EPROM is a special type of PROM that can be erased by exposing it to ultraviolet light.

EEPROM (electrically erasable programmable read-only memory): An EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge.

SECONDARY MEMORY –

Secondary memory is available on mass storage devices for permanent data storage. Data stored on a secondary device is retained even when it is not supplied any power. This data can be transported in most cases, and looks and appears the same on any machine, irrespective of where the data was first copied onto the secondary storage device.

Secondary memory is not directly accessible by the computer. When a computer needs to run or execute an application stored in secondary memory, it first brings it to primary memory storage for a while, to control and carry out its execution. Once execution of the application is done, the processor releases the application and restores its control and memory data with the secondary memory devices.

The essential data storage techniques of the '50s and '60s where punch tapes and punch cards.

Punch Tapes: A 0.1 mm thick paper strip was used to store data in the form of punched holes. A keyboard was used to punch the desired alphabet onto the tape. This alphabet was represented on the tape by a certain number and a select pattern of holes.

Punch Cards: Primarily used in textile and handloom industries, punch cards stored instructions of operation for machines. Early digital computers made punch cards popular as data storage assemblies. Their working is pretty much similar to that of punch tapes, except for the fact that instead of paper strips, this technique uses cards about 3¼ inches

× 7⅜ inches in size.

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Magnetic tape – Magnetic tape is a recording technique invented in 1928. This formed the basis for magnetic digital information storage. This form of data storage gained immense popularity in the '70s, when magnetic tapes were wound around 10.6-inch reels.

The device used for the read-write operations on these tapes is called a tape drive. Until the early 1980s, magnetic tape drives were huge external devices. With the introduction of IBM's 3480 family of magnetic tape cartridges, most magnetic tape storage assembly went inside the central processing unit.

Floppy Disk - The floppy disk memory technique uses a thin plastic-coated film covered with magnetic material. It is covered with a protective plastic cover. Initially developed by IBM as inexpensive microcode feeders in 1967, floppy disks were made commercially available in 1971 to the public. Floppy disks began as giant 8-inch diskettes, and eventually evolved into 5¼-inch diskettes, and later 3½-inch diskettes.

Optical Drives (CD/DVD) - Philips and Sony collaborated in the '70s on a project to create a new digital audio disc. This collaboration brought together the optical disc drive technologies both the companies were earlier separately working on. Launched in 1982-

83, the Compact Disc (CD) eventually went on from being an audio disc to a data storage device.

Hard Disc Drives - The dominant technique for storing data in current times, a hard disk consists of rapidly rotating discs with a magnetic head to read and write data. Data can be accessed randomly. HDDs were introduced by IBM (Yes, again IBM!) around the late

1950s for real-time transaction processing machines. A few years later, IBM commercially launched the IBM 1311 model, which was almost as big as a dishwasher, and had the capacity to store about 2 million characters.

Flash drives - A flash drive is a data storage device that uses flash memory for storage purposes. Typical in design, flash drives are light-weight and small in design; and are hence easily portable. Flash drives operate from the power supplied by a computer's USB port (the port in which they are plugged in). The data on it can be erased and reprogrammed as per the user's requirements. Low cost, minimal power consumption, and portable features make flash drives extremely desirable and popular in modern times.

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Check your progress – 2

a) The CPU calls instructions and data from the computer's ……………….

b) ………….. Memory is used for immediate access of data by the processor.

c) A computer's …………… is the memory used to store data and programs on a temporary basis.

d) …………… is a type of memory that is data can only be accessed and read by the user.

e) ……………… memory is not directly accessible by the computer.

f) ………………….. is a recording technique invented in 1928.

g) A ……………… is a data storage device that uses flash memory for storage purposes.

1.4 COMPUTER LANGUAGE AND ITS TYPES

Learning Objective :-

After studying this sub unit you would be able to – i. Define computer language ii. Explain different types of computer languages

Computer languages are the languages by which a user command computer to work on the algorithm which a user has written to get an output.

Why we need computer language? Because, computer understands only the computer language, the computer don‘t understand our languages like English, Hindi, Punjabi etc. So we have to give instructions in one of the computer languages.

Types of Computer Language

To communicate with the computer user also needs to have a language that should be understood by the computer. As we human beings communicate with each others in different language such as Urdu, French, Punjabi and Arabic etc. Similarly to communicate with the computers we have to use specific languages and for this purpose, different languages are developed for performing different types of work on the computer. Basically, languages are divided into two categories.

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1. Low Level Languages.

2. High Level Languages.

LOW LEVEL LANGUAGES –

Low-level languages are considered to be closer to computers. Programs and applications written in low-level language are directly executable without any interpretation or translation. Low level computer languages are machine codes. Computer cannot understand instructions given in high level languages or in English. It can only understand and execute instructions given in the form of machine language i.e. language of 0 and 1. There are two types of low level languages:

Machine Language.

Assembly Language

Machine Language –

It is the lowest and most elementary level of Programming language and was the first type of programming language to be developed. Machine Language is basically the only language which computer can understand, which is represented inside the computer by a String of binary digits

(bits) 0 and 1. The symbol 0 stands for the absence of Electric pulse and 1 for the presence of an electric pulse. Since a computer is Capable of recognizing electric signals, therefore, it understands machine Language.

Advantages of Machine Language

It makes fast and efficient use of the computer.

It requires no translator to translate the code i.e. Directly understood by the computer

Disadvantages of Machine Language:

All operation codes have to be remembered

All memory addresses have to be remembered.

It is hard to amend or find errors in a program written In the machine language

These languages are machine dependent i.e. a particular Machine language can be used on only one type of computer

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Assembly Language –

Assembly languages have the same structure and set of commands as machine languages, but they enable a programmer to use names instead of numbers. This is another low level but a very important language in which operation codes and operands are given in the form of alphanumeric symbols instead of 0‘s and l‘s. These alphanumeric symbols will be known as mnemonic codes and can have maximum up to 5 letter combination e.g. ADD for addition, SUB for subtraction,

START, LABEL etc. Because of this feature it is also known as ‗Symbolic Programming

Language‘. This language is also very difficult and needs a lot of practice to master it because very small English support is given to this language.

In the early days of programming, all programs were written in assembly language. Programmers still use assembly language when speed is essential or when they need to perform an operation that isn't possible in a high-level language.

Advantages of Assembly Language

It is easier to understand and use as compared to machine language.

It is easy to locate and correct errors.

It is modified easily

Disadvantages of Assembly Language

Like machine language it is also machine dependent.

Since it is machine dependent therefore programmer should have the knowledge of the hardware also.

HIGH LEVEL LANGUAGE –

A programming language such as C , FORTRAN or Pascal that enables a programmer to write programs that are more or less independent. Such languages are considered high-level because they are closer to human languages. The main advantage of high-level languages over low-level languages is that they are easier to read, write, and maintain.

High level computer languages give formats close to English language and the purpose of developing high level languages is to enable people to write programs easily and in their own native language environment (English). High-level languages are basically symbolic languages that use English words and/or mathematical symbols rather than mnemonic codes.

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As computer does not understand the high level language so, programs written in a high-level language are translated into machine language by a compiler or interpreter . The first high-level programming languages were designed in the 1950s.

The various High – Level Languages are:-

BASIC – Beginners All Purpose Symbolic Instruction Code

FORTRAN – Formula Translation

COBOL – Common Business Oriented Language

PASCAL – Named after Blaisé Pascal

C – The latest and most powerful language.

Advantages of High Level Language

User-friendly

Less time is required to write the program.

Easier to learn

Easier to maintain.

Program written in High level language are easier to debug the error.

Program written in high level language are largely machine independent.

Program developed on one computer can be run on another with little or no modification.

Disadvantages of High Level Language

A high-level language has to be translated into the machine language by a translator and thus a price in computer time is paid.

The object code generated by a translator might be inefficient Compared to an equivalent assembly language program

A long sequence of statements is to be written for every program

Check your progress – 3

a) Computer understands only the ……………… language.

b) Programs and applications written in ……………………… are directly executable.

c) …………………. is the only language which computer can understand.

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d) …………………..enable a programmer to use names instead of numbers.

e) …………………… are symbolic languages that use English words and/or mathematical symbols.

1.5 OPERATING SYSTEM

Learning Objective :-

After studying this sub unit you would be able to – i. Define operating system ii. Explain DOS and windows iii. Explain security and antivirus

An operating system is a program that manages the computer hardware. It also provides the basis for application programs and acts as an intermediary between a user of a computer hardware.

Some operating systems are designed to be convenient, others to be efficient, and others some combination of two.

What is an operating system?

An operating system is an important part of almost every computer system. A computer system can be divided into four components: the hardware, operating system, the application programs, and the users.

The hardware (the central processing unit (CPU), memory and the input/output devices) – provides the basic computing resources.

The application programs (such as word processors, spreadsheets, compilers and web browsers) - define the ways in which these resources are used to solve the computing programs for the various users.

The operating system controls and coordinates the use of the hardware among the various application programs for the various users.

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The components of the computer system are its hardware, software and data. The operating system provides the means for the proper use of these resources in the operation of the computer system. An operating system is similar to a government. Like a government, it performs no useful function by itself. It simply provides an environment within which other programs can do useful work.

Fig 1.8 what is operating system

Operating systems perform basic tasks, such as recognizing input from the keyboard , sending output to the display screen , keeping track of files and directories on the disk , and controlling peripheral devices such as disk drives and printers .

An Operating System can be of Three Types:

Single User MS-Dos, MS-Win 95-98, Win-ME

Multi User UNIX, Linux, XENIX

Network Novel Netware, Win-NT, Win-2000-2003

Single User: If the single user OS is loaded in computer‘s memory; the computer would be able to handle one user at a time.

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Multi user: If the multi-user OS is loaded in computer‘s memory; the computer would be able to handle more than one user at a time.

Network:

If the network OS is loaded in computer‘s memory; the computer would be able to handle more than one computer at time.

Microsoft is an American company that in 1975 was founded by Bill Gates and Paul Allen. The company headquarters in Redmond, Washington. Main activity is the development of basic computer software such as operating systems, development tools, office applications and databases.

Operating systems that Microsoft has developed the firm are divided into two groups:

MS-DOS (Microsoft Disk Operating System)

Windows (Brand name for the Microsoft Windows operating system)

1.5.1 DOS AND WINDOWS

Operating systems provide a software platform on top of which other programs, called application programs, can run. The application programs must be written to run on top of a particular operating system. For PCs , the most popular operating systems are DOS, OS/2 , and Windows but others are also available, such as Linux .

DOS –

DOS "Disk Operating System." DOS was the first operating system used by IBMcompatible computers. It was originally available in two versions that were essentially the same, but marked under two different names. "PC-DOS" was the version developed by IBM and sold to the first IBM-compatible manufacturers. "MS-DOS" was the version that Microsoft bought the rights to, and was bundled with the first versions of Windows.

MS-DOS (Microsoft Disk Operating System) is an operating system for x86 -based personal computers . MS-DOS Originally developed by Microsoft for IBM , MS-DOS was the standard operating system for IBM-compatible personal computers .MS-DOS originally written by Tim Paterson and introduced by Microsoft in August 1981 .

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American computer programmer Timothy Paterson, a developer for Seattle Computer Products, wrote the original operating system for the Intel Corporation

‘s 8086 microprocessor in 1980, initially calling it QDOS (Quick and Dirty Operating System), which was soon renamed 86-

DOS. A year later, fledgling company Microsoft purchased exclusive rights to sell the system, renamed MS-DOS, to IBM for their newly developed IBM-PC. IBM-compatible versions were marketed as PC-DOS. Version 1.0 was released in 1981; additional upgraded versions kept pace with the rapidly evolving PC. Windows 95, introduced by Microsoft in 1995, incorporated MS-

DOS 7.0 but ultimately superseded the MS-DOS platform. Starting with Windows NT,

Microsoft‘s operating systems were designed independently of MS-DOS, though they were capable of running some MS-DOS applications.

Although MS-DOS enjoyed enormous popularity in the 1980s and early 1990s, the technology did not always keep pace with its competition. The system lacked the

Multitasking ,

Multiuser capabilities of the UNIX operating system

Ms-dos was limited to a command line interface

In contrast to the user-friendly graphical user interface (GUI) of the early Macintosh computer from Apple Inc.

Although MS-DOS ceased to be marketed as a stand-alone operating system, the relatively simple, stable platform is still used in some embedded computer systems.

Different version of DOS, such as 2.0, 3.0, 3.2, 4.0, 5.0, 6.0, 6.2, 6.22, 7.0, 7.2 are available. The higher versions have more features and commands. However, the basic commands and features are available in all versions.

Structure information

16-bit operating system, (formerly 8-bit)

Single tasking

Command interpreter for internal and external commands

External driver software imbedding for periphery devices possible

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System environment

Minimum: 512 kbytes RAM, 5 mbyte hard disk storage (depends on version for full installation)

FAT file system

Executable with every x86 compatible CPU

Low RAM and fixed storage disk needs

Field of Application

Booting system for storage media

File management

For single user systems only

Network client (NetBEUI, IPX/SPX, TCP/IP)

Batch processing

MICROSOFT WINDOWS –

Windows OS, computer operating system (OS) developed by Microsoft Corporation to run personal computers (PCs). Featuring the first graphical user interface (GUI) for IBM -compatible

PCs, the Windows OS soon dominated the PC market. Approximately 90 percent of PCs run some version of Windows.

The first version of Windows 1.0 was introduced in 1985, was simply a GUI offered as an extension of Microsoft‘s existing disk operating system, or

MS-DOS . Based in part on licensed concepts that Apple Inc.

had used for its Macintosh System Software, Windows for the first time allowed DOS users to visually navigate a virtual desktop, opening graphical ―windows‖ displaying the contents of electronic folders and files with the click of a mouse button, rather than typing commands and directory paths at a text prompt.

WINDOWS was similar to APPLE Mach operating system interface on IBM-PC. The main features of windows are

Easy to use graphical user interface (GUI)

Device independent graphics

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Multitasking support.

WINDOWS-95 released in 1995 is a 32-bit operating system which includes MS-DOS7.0 and takes control of computer system after starting.

Versions of Microsoft's window operating system are:

Windows XP / Vista / 7 / 8 (home and professional versions for end users)

Windows Server (server versions of the extension as 'SQL Server', 'Exchange Server' and others)

Windows CE / Mobile / RT (special versions for Pocket PC - Mobile Devices)

Advantages of using windows –

Ease of use

Available software

Support for new hardware.

Compatibility with MS driven websites.

Disadvantages of using Windows

High resource requirements

Poor security

Virus susceptibility

Outrageous license agreements

Poor stability

1.5.2 SECURITY AND ANTIVIRUS

SECURITY –

In the computer, the term security or computer security -- refers to techniques for ensuring that data stored in a computer cannot be read or compromised by any individuals without authorization. Most computer security measures involve data encryption and passwords.

Data encryption is the translation of data into a form that is unintelligible done without converting the data.

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A password is a secret word or phrase that gives a user access to a particular program or system .

Computer security is the process of preventing and detecting unauthorized use of your computer.

Prevention measures help you to stop unauthorized users (also known as "intruders") from accessing any part of your computer system. Detection helps you to determine whether or not someone attempted to break into your system, if they were successful, and what they may have done

.

Computer security is that branch of information technology which deals with the protection of data on a network or a stand-alone desktop. As every organization is dependent on computers, the technology of its security requires constant development. Here are the different types of computer security.

There are essentially two major types of computer security –

Software security - Software security usually consists of server protection and security, system security from viruses and other malicious software programs, and data security through theft prevention and safe computer practices. Computer network security can be disrupted or encroached in the following ways:

Trojan Horse - Trojan horse is common and one of the most potential threats to computer security. They are malicious and security-breaking programs. They are a useful tool for hackers who try to break into private networks. Hackers generally attach Trojan horse to a file, which triggers a virus or remotely controlled software, giving the hacker complete control over the computer.

Viruses and Worms - Viruses and worms are well-known for their destructive nature and the property of replicating themselves. They are basically pieces of computer program codes, which are written by hackers and other computer geniuses.

Sniffing - Sniffing is the act of intercepting TCP/IP packets while they are getting transferred on a network. The interception generally takes place through simple eavesdropping done by a hacker.

Hardware security - Hardware security usually consists of physical devices, including server mainframes, computers, and external or portable memory and storage devices.

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Protection –

The internet offers access to a world of products and services, entertainment and information. At the same time, it creates opportunities for scammers, hackers, and identity thieves. If malicious software infects your computer it can stop it working properly, can delete or corrupt your files and can allow others to access your computer and your confidential information.

Computer facilities have been physically protected for three reasons:

To prevent theft of or damage to the hardware

To prevent theft of or damage to the information

To prevent disruption of service

Strict procedures for access to the machine room are used by most organizations.

Things you can do to protect your computer are:

Use security software

Practice the principle of least privilege (PoLP)

Maintain current software and updates

Frequently back up important documents and files

Avoid threats to your computer

Never share passwords or passphrases

Do not click random links

Beware of email and attachments from unknown people

Do not download unfamiliar software off the Internet

Do not propagate virus hoaxes or chain mail

Log out of or lock your computer

Shut down lab/test computers

Remove unnecessary programs or services

Restrict remote access

Treat sensitive data very carefully

Remove data securely

Employ encryption whenever it is available

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ANTIVIRUS –

Antivirus is a utility that searches a hard disk for viruses and removes any that are found. Antivirus software is a program or set of programs that are designed to prevent, search for, detect, and remove software viruses, and other malicious software like worms, trojans, adware, and more.

These tools are critical for users to have installed and up-to-date because a computer without anti-virus software installed will be infected within minutes of connecting to the internet. The bombardment is constant, with anti-virus companies update their detection tools constantly to deal with the more than 60,000 new pieces of malware created daily.

There are several different companies that build and offer anti-virus software and what each offers can vary but all perform some basic functions:

Scan specific files or directories for any malware or known malicious patterns

Allow you to schedule scans to automatically run for you

Allow you to initiate a scan of a specific file or of your computer, or of a CD or flash

 drive at any time.

Remove any malicious code detected –sometimes you will be notified of an infection and asked if you want to clean the file, other programs will automatically do this behind the scenes.

Show you the ‗health‘ of your computer

Always be sure you have the best, up-to-date security software installed to protect your computers, laptops, tablets and smartphones.

Check your progress – 4

a) The ………………….. controls and coordinates the use of the hardware.

b) ………… was the first operating system used by IBM-compatible computers.

c) DOS is a …………… operating system.

d) ………………….. is a 32-bit operating system.

e) ………………… is the process of preventing and detecting unauthorized use of your computer.

f) Antivirus is a utility that searches a hard disk for

………..

and removes any that are found.

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Let Us Sum Up (Summary)

1.

Computers are machines that perform tasks or calculations according to a set of instructions, or programs.

2. An input device is anything that puts information inside the computer such as Keyboard,

Mouse, Scanner, Microphone etc.

3. An input device is anything that display information such as Monitors, Printers, Audio

Output Devices.

4. There are three different types of computers based on the principles of operation analog, digital and hybrid.

5. FOSS programs are those that have licenses that allow users to freely run the program for any purpose, modify the program as they want, and also to freely distribute copies of either the original version or their own modified version.

6. Primary Memory (also called main memory) is used for immediate access of data by the processor.

7. RAM stands for Random Access Memory that is both write data into RAM and read data from RAM.

8. ROM stands for Read Only Memory that is data can only be accessed and read by the user.

9. Secondary memory is available on mass storage devices for permanent data storage.

10. Computer languages are the languages by which a user command computer to work on the algorithm which a user has written to get an output.

11. Low level computer languages are machine codes.

12. There are two types of low level languages: Machine Language and Assembly Language

13. A high level language such as C , FORTRAN or Pascal that enables a programmer to write programs that is more or less independent.

14. The operating system controls and coordinates the use of the hardware among the various application programs for the various users.

15. Security or computer security refers to techniques for ensuring that data stored in a computer cannot be read or compromised by any individuals without authorization.

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Answers

Check your progress -1

a) Store, retrieve and process

b) Instruction

c) Input

d) Twelve

e) Scanner

f) Analog, digital

g) Charles babbage

h) Machine language

Check your progress – 2

a) Memory

b) Primary

c) RAM

d) ROM

e) Secondary

f) Magnetic tape

g) Flash drive

Check your progress – 3

a) Computer

b) Low level language

c) Machine language

d) Assemble language

e) High level language

Check your progress – 4

a) Operating system

b) DOS

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c) 16 – bit

d) Windows 95

e) Computer security

f) Viruses

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Course -7 Basic Computer Skills

Unit-2

WORD

Windows, the operating system, helps to connect each element of personal computer together but it cannot perform practical tasks such as letter writing and calculating bills. For these jobs we need some additional soft wares known as applications or programs that are designed to perform specific tasks. Most of the personal computers come with a package of programs which are already installed. One of the most popular packages is Microsoft Office.

Office consists of several individual programs such as Word, Excel/Spreadsheet, Power-point and Outlook. They are quite sophisticated programs capable of doing tremendous tasks with

their array of usage being very wide.

2.1 Microsoft Word:

Word is an extremely powerful word processor which is capable of producing ‗written‘ documents of all kinds including letters memos newsletters and posters. You have the option to create documents from scratch or for many types of documents to use one of the programs wizards or templates. The wizards let you chose the content and how the document looks while the templates have a preset layout.

Opening the program:

Opening a program and creating a new document will be among the first things you do on your computer. The process is similar in most programs of the MS family. To open a word document following steps should be applied-:

Click the left mouse button once at the START at the bottom left of the screen

1. Point at ALL PROGRAMS and click the left mouse button once so that some icons appear on the right

2. Point at MS Office and click the left mouse button, and then press the ENTER key

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As a result Microsoft Office word Document Window appears, filling the whole screen.

At the top of the window is the blue Title bar, indicating that this is Document 1. Below that is the Menu bar, containing the names of various menus, and below the Menu bar are the two rows of buttons, and the Ruler. Down the right hand side and near the foot of the screen are the two scroll bars, with arrows at each end

2.2 Creating a File:

As we go to the File menu and click on NEW , a new file opens on the screen. This enables you to creat and modify documents with ease. Before starting typing one should first specify the size and orientation of the document, size of its margins, and size of the paper you want to print on.

To do this go to the File menu and click on Page Setup. Click on the margin boxes and enter your settings, then click OK.

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To enter a text, just type on the keyboard. As you type, the words will appear at the cursor position on your screen. When you reach the end of a line, the text will automatically flow to the next line. To start typing on a new line before reaching the end of the current one press the

Enter key on the keyboard and continue to type. If you make a mistake use Backspace key to delete the last character you have typed. The Backspace key is at the top right of the main part of the keyboard, marked with a left pointing arrow.

2.3 Setting the text: Selecting text

Open the file FOCUS. Choose the Open command from the File menu. Double-click on the file name FOCUS.

Note that you could have opened the file as before, by clicking on the file name and then clicking on the

Open button. Double-clicking on the name of the file is a useful shortcut.

To delete a piece of text, or to make changes to it, the text must first be selected (highlighted).

To select a word, double-click on it.

To deselect a piece of text, click with the pointer somewhere else.

To select a whole line, point in the left margin (the pointer becomes arrow-shaped) and click.

To select a paragraph, triple-click in the paragraph (

not

in the margin). Select the last paragraph in this way.

To select a sentence, hold down the

CTRL

key and,

keeping it depressed,

click the left mouse button with the pointer somewhere in that sentence. This is known as

"

CTRL

+click". Select the last sentence in this way.

To select the whole text, choose the Select All command from the Edit menu. Try this. Alternatively, you can triple-click in the margin.

To select a phrase, drag over it. For example, to select, move the pointer to the place from where to start highlighting press

and hold down

the left mouse button, and drag over the two words, letting go of the mouse button when both words are highlighted.

Another way of selecting a phrase is by extending the highlight, using the

SHIFT

key. Place the insertion point in the first word to be selected, and then hold down the

SHIFT

key and,

keeping it depressed,

click the left mouse button with the pointer in the last word to be selected. This is known as "SHIFT+click".

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To select part of a word, the highlight is extended using the SHIFT key in conjunction with the direction keys, marked with arrows. Place the insertion point before the first character to be selected, and then hold down the SHIFT key and,

keeping it depressed,

press the appropriate direction key.

To move the insertion point up or down one page, click on the double upwards-pointing and double downwards-pointing triangles near the bottom of the vertical scroll bar.

To move the insertion point to the beginning or end of the text, press

CTRL

+

HOME

or

CTRL

+

END

.

This means "hold down the

CTRL

key and,

keeping it depressed,

press

HOME

or

END

".

To move the insertion point to the beginning of a specified page, use the Go To command:

Choose the Go To command from the Edit menu; the Find and Replace dialogue box appears

Type 2 to go to page 2

Click on the Go To button to confirm your choice

Click on the Close button to make the dialogue box disappear

At the foot of the screen, Word confirms that the insertion point is on page 2. Click a few times on the upwards-pointing scroll button to see that the insertion point is at the top of the page (indicated by a line of dots).

Once the text is highlighted it is ready for setting or Style.

Placing the insertion point:

Use the mouse to move the I-beam pointer so that it is slightly to the left of the first letter of the first line, and click the left mouse button. The insertion point should move to this position.

Check that the insertion point is a flashing vertical bar and not a block.

Inserting text:

With the insertion point followed by a space, notice the words moving along as new text is inserted and the text is tidied so that the words do not overshoot the right-hand margin.

Deleting text:

Pressing the

BACKSPACE

key deletes the character to the

left

of the insertion point. To change

1503 to 150, place the insertion point slightly to the right of 1503 and

lightly

press

BACKSPACE

.

The 3 should disappear.

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Pressing the

DELETE

key deletes the character to the

right

of the insertion point. To delete the words in the last paragraph, place the insertion point to the left of these characters and keep pressing the

DELETE

key

lightly

until the words disappear.

Inserting a new line:

Place the insertion point immediately to the left of the first line; again, check that the insertion point is a flashing vertical bar. Press ENTER twice: this inserts two blank lines at the top of the text.

Place the insertion point on the first of the new blank lines and type whatever you want.

Splitting a line:

To split the first paragraph into two, place the insertion point just before I at the beginning of the sentence and press ENTER twice. If you accidentally split the line in the wrong place, you should press BACKSPACE immediately to delete the unwanted "enter" character.

Joining lines:

To join the two paragraphs, place the insertion point immediately after the last word of the

first paragraph, and press

DELETE

twice. This deletes the two "enter" characters that were inserted when you pressed the

ENTER

key.

It will be necessary to insert a space between the full stop and beginning of first letter of

the next sentence.

Font:

Window offers a range of fonts (particular styles of typing). Go to the format menu and click on Font. To view the list of fonts, click on the arrow. Click on your choice of font.

Highlighted portion becomes in chosen font.

If you find that the writing is rather small, and that the text occupies only part of the width of the screen, you can make the text easier to read, using the Zoom command from the View menu as follows:

Use the mouse to move the pointer so that it is pointing at the word View in the Menu

Bar

With the tip of the arrow pointer on the word View, click the left mouse button once; the

commands

in the View menu appear.

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Use the mouse to move the pointer to the word Zoom in the View menu and click the left mouse button once; this action is known as "choosing a command". The Zoom window, or

dialogue box,

appears.

Use the mouse to move the pointer to the words Page width in the dialogue box and click the left mouse button once; a dot should appear to the left of these words

Use the mouse to move the pointer to the OK button in the dialogue box and click the left mouse button once; the dialogue box disappears and the text is now enlarged and extends across the full width of the screen

Underline:

You can underline text in number of ways. Click on the arrow next to the Underline box.

Scroll through the options and click on your choice. If you do not want text to be underlined ensure that None is selected.

Effects:

You are presented with a number of special effects that you can apply to your text. To choose one , click in the relevant box, a tick will appear. Click the box again to remove the

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effect. Once you have chosen a font, you can also select a font style for it. Typically, you can choose whether your text appears in a regular format, or in italics or in bold. To select a font style, click on your choice from the Font Style box.

Size:

The size of the box is measured in points. The greater the point size, the larger the text.

However point sizes are not uniform across all the fonts. To alter the font size , scroll through and click on your choice in the Size box. A good thumb rule is not to use text smaller than 8pt, as it becomes difficult to read.

Colour:

To alter the colour of the text, click on the arrow next to the colour box, scroll through the colours and click on your choice. Remember that too many colours on one page may be overpowering.

When you have finished editing a piece of text (or document) you should Close it. To do this, choose the Close command from the File menu as follows:

Click on the word File in the Menu Bar to pull down the File menu

Click on the word Close in the list of commands to choose that command

The text and its window should disappear but you still have a copy of it on your file space.

2.4 Editing And Page Formatting:

Setting up a new piece of text: the New command:

To set up a new piece of text, you must choose the New command from the File menu:

Click on File to pull down the File menu

Click on New to choose the New command

On the right-hand side of the screen a list of possible kinds of New Documents appears:

Click on Blank Document; a new, empty, document window will appear

Type few. Now save this new document with the file name Doctor as follows:

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Pull down the File menu

Choose the Save command

Type the name Doctor in the File name box (the suggested name will disappear as soon as you start typing)

Click on the Save button

Changing your mind about using a menu or dialogue box Making a menu disappear:

Note that if you pull down a menu by mistake, you can make the menu disappear by clicking somewhere else on the screen. Try this as follows:

Pull down the Help menu by clicking on its title

Click somewhere else on the screen to make the menu disappear

Making a dialogue box disappear:

follows:

You can make a dialogue box disappear by clicking on the Cancel or Close button. Try this as

Pull down the File menu

Choose the Open command by clicking on it

In the Open dialogue box, click on the Cancel button to make the dialogue box disappear

Making changes to an existing file: the Open command

Remember that the New command from the File menu is used for setting up a

new

piece of text.

To edit an

existing

piece of text, the Open command is used.

You have a file whose name is TARGET and which contains some mistakes. Open this document as follows:

Pull down the File menu

Choose the Open command

The Open dialogue box appears, containing, amongst other items, a list of your Word files. To open

TARGETS:

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Click on TARGETS to select (highlight) it

Click on the Open button

The text of TARGETS appears on the screen, ready for editing.

Moving and copying blocks of text:

You might wish to move a block of text (a paragraph, or a phrase or word, for example) from one part of the document to another, or you might wish to copy a block of text several times.

Moving a block of text:

Text can be moved from one place to another within a document using the Cut and Paste commands from the Edit menu as follows:

Select the text to be moved

Choose the Cut command from the Edit menu

A copy of the text goes to a special part of the computer's memory sometimes called the

Clipboard.

The contents of the clipboard can be pasted in the text as follows:

Move the insertion point to the place before which the text is to be inserted

Choose the Paste command from the Edit menu

For example, try changing the order of the sentences in the last paragraph as follows:

Select the first sentence of the last paragraph (remember

CTRL

+click to select a sentence)

Choose the Cut command from the Edit menu

Click after the last sentence of the last paragraph

Choose the Paste command from the Edit menu

Copying a block of text:

Text can be copied in a similar way:

Select the text to be copied

Choose the Copy command from the Edit menu

Move the insertion point to the place before which the text is to be inserted

Choose the Paste command from the Edit menu

The contents of the Clipboard may be copied several times, and a floating Clipboard box enables you to copy several different pieces of text which have been copied to the Clipboard.

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Try inserting some extra instances of the words officially recorded before sets of triplets and sets of quadruplets in this way.

Placing the contents of one file into another:

You might wish to place a copy of one file into another; for example, you might wish to put a copy of a file containing an address into a file containing a standard letter. To place a copy of a file into the text in the document window:

Move the insertion point to the place before which the text is to be inserted

Choose the File command from the Insert menu

(not

the Open command from the File menu)

In the File dialogue box, click on the name of the file to be inserted

Click on the Insert button

More shortcuts: using the Standard Toolbar The New, Open and Save commands:

The Standard Toolbar is just below the Menu Bar, and it too contains a series of buttons which can be used to speed up your work. For example, the group of three buttons at the left-hand end can be used to give the New, Open and Save commands, thus by-passing the File menu.

Point at each of these buttons in turn, slowly, and the ScreenTip will indicate the name of each button.

Try clicking on the middle button of this group of three (shaped like a folder); the Open dialogue box appears. Close the dpen dialogue box by clicking on the Cancel button or by pressing the

ESCAPE

key.

Change the Print button as follows:

Choose the Customize command from the Tools menu

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Click on the Commands "tab" in the tab dialogue box

Scroll down the list of commands on the right and notice that there are two Print buttons available: Print and Print...

Remove the Print button from the real toolbar by dragging it down into the text

Add the Print button to the toolbar by dragging it from the dialogue box up to the real toolbar, next to the Save button

Click on Close to confirm choice

The Close and Exit buttons:

If you have used MS-Office before you will know that at the three buttons at the very top right on the screen can be used to Minimize the window, Resize or Maximise the window, and Close the window.

If there are two Close (X) buttons on the screen, the lower one is a shortcut to the Close command (the current document is closed) and the upper one is a shortcut to the Exit command (for leaving Word).

Click on the Close button to close the current document, and do not save the changes

Normal View and Print Layout View:

Open TARGET using the Open button.

MS-Office displays the text in Normal View (this is what has been used up to now in the course) and also in Outline View or in Print Layout View. Although some people prefer to work in Print Layout View, the author of these notes prefers Normal View, and these notes assume that the reader is using Normal View at present.

Pull down the View menu and check that the "button" to the left of the Normal command is highlighted.

If a different button is highlighted, then the wrong view is selected; choose the Normal command to return to the Normal View.

Five buttons near the bottom left of the screen (above the Page number) provide a shortcut to these commands: point at each one in turn and notice that the ScreenTip shows that they are, from left to right,

Normal View, Web Layout View, Print Layout View, Outline View, Reading Layout. The leftmost of these buttons should be highlighted.

More shortcuts: autocorrect:

Without closing already opened file, use the New command or button. Try to type the following piece of text exactly and see what happens:

(c) 1/2 1st <=> :)

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Now try the following (complete with deliberate mistakes):

Teh CAt sat onthe MAt on a monday. he was affraid i think.

Office may automatically correct some of your mistakes and this can be a useful feature. Sometimes, however, you will not want the change to be made. For example, to prevent Office from automatically changing (c) to © try the following:

Choose the AutoCorrect Options command from the Tools menu

Click on (c) to select it

Click on the Delete button

Look at the other options in the AutoCorrect dialogue box

Click on the OK button

Try to type (c) again

Close the current piece of text without saving it.

Working in inches rather than centimetres:

Your system may have been arranged so that the Ruler is marked off in centimetres, whereas the tab stops (faint marks on the bottom of the Ruler) are every half an inch. It may be sensible, therefore, to arrange for the Ruler to be marked off in inches. Do this as follows:

Choose the Options command from the Tools menu

In the Options dialogue box, bring the General index card to the front

At the foot of the "card", there is a section which deals with Measurement units; click on the V to the right of Centimeters

Click on Inches in the drop-down list

Click on the OK button

The Ruler should now be marked off in inches.

The margins:

The default margins:

By default, the text is printed with a top and bottom margin of 1 inch each, and with a left and a right margin of 1.25 inches. The margins remain the same for the whole document, although the indent can be changed relative to the margins.

55

Changing the margins:

To change the margins:

Choose the Page Setup command from the File menu

In the Page Setup dialogue box, ensure that the Margins index card is at the front

Change the Top, Bottom, Left and Right margins as appropriate, either by typing the new value or by pressing

UP

and

DOWN

Click on the OK button

The margins should not be set at less than half an inch, as many laser printers cannot print very near to the edge of the paper.

Special characters:

Office allows you to include many special characters which do not appear on the keyboard. For example, to type the character n

Choose the Symbol command from the Insert menu

Check that the Symbols index card is at the front and change the fount to Symbol ("font" is the American spelling of the English word "fount")

In the Symbol dialogue box, scroll down until you see on the square containing a n and then click on it

Click on the Insert button Try this.

Special characters can be selected from other founts: scroll down the list in the Font box.

For

accented

characters, change the fount to (normal text) (at the top of the fount list).

Finally, click on the Close button to close the Symbol dialogue box; there is no need to close this dialogue box after each special character has been inserted, although it will be necessary to make the document window and the Symbol window active in turn by clicking in them.

2.5 Printing and previewing the text:

Print preview:

It is important to preview your text before you print it, to check that the layout is correct, and that there are no headings at the foot of a page.

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Preview the file is as follows:

Choose the Print Preview command from the File menu

A representation of the page appears on the screen. To see the next page, press

PAGE DOWN

, and to see the previous page, press

PAGE UP

.

Use the mouse pointer to point at the page; it is in the shape of a magnifying glass. Click in the page for a magnified view. Use the scroll bar to move around the document.

With the mouse pointer still in the shape of a magnifying glass, click in the document again to see a representation of the whole page.

Return to the normal view by clicking on the Close button on the Toolbar.

Close the file by choosing the Close command from the File menu.

Printing the text:

Open the file TARGET

Choose the Print command from the File menu; the Print dialogue box appears

Unless you wish to go ahead with printing, click on the Cancel button

Printing only part of a document:

As mentioned above, long pieces of text such as books or theses should be divided into several files, perhaps one chapter per file. Often it will be necessary to make a small change to one page, and you will not wish to print the whole file. To print only part of the document:

Choose the Print command from the File menu

In the Page range section of the Print dialogue box, click on the Pages button

Type the numbers of the pages to be printed as indicated by MS-Office

Click on the OK button to confirm your choice

The Save command Choosing Save from the File menu:

When you have finished typing or editing a piece of text, you must save it so that you have a permanent copy of it.

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Using the mouse, point at the word File in the Menu Bar and click the left mouse button. The File menu appears, with the commands New, Open, Close. Choose the Save command by clicking on it. If all goes well, the Save As dialogue box appears.

2.6 Saving the text:

The File name box contains a suggested name for the file. Give the file a shorter name,

TARGET, as follows:

Type the word TARGET (as soon as you start typing, the highlighted contents of the File name box will disappear)

Click on the button labelled Save to confirm that you wish to save the file as TARGET

The dialogue box disappears and after a few seconds the name of the file TARGET.doc appears in the title bar of the document window. The .doc extension indicates that the file was created using MS-

Office.

If your text already has a name when you use the Save command, MS-Office will save the text with the same name and the old version will be lost. Make some changes to the text. Now choose the Save command from the File menu again. This time no dialogue box appears, because MS-Office does not need to ask for a file name and the text is saved as TARGET again. The old version is lost.

You may wish to save the changes in a file with a new name, so that there are two versions of the text. This time, choose the Save As command from the File menu. The Save As dialogue box appears, with the current name, TARGET, highlighted in the File name box. To give the text a new name, type

FOCUS and the highlighted old name disappears as soon as you start typing. Click on the Save button to confirm the new name. There are no more changes to be made to this text, so the window should be closed as before, by choosing the Close command from the File menu.

2.7 Save an MS-Office Word file in another file format:

We can save MS-Office Word documents to any of several file formats. You cannot use MS-

Office to save a document as a JPEG (.jpg), GIF (.gif) file, and as a PDF (.pdf) file. Click the

Microsoft Office Button and then click Save As. To view all of the possible file formats, in the

Save As dialog box, click the arrow to the right of the Save as type list, and then click the file type that you want. The list of various type of files is given below:

FOR THIS TYPE OF FILE CHOOSE

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.docx

.docm

.doc

.dotx

.dotm

.dot

.pdf

.xps

.mht (MHTML)

.htm (HTML)

.htm (HTML, filtered)

.rtf

Word Document

Word Macro-Enabled Document

Word 97-2003 Document

Word Template

Word Macro-Enabled Template

Word 97-2003 Template

PDF

XPS Document

Single File Web Page

Web Page

Web Page, Filtered

Rich Text Format

.txt

.xml (Word 2007)

.xml (Word 2003)

.wps

Plain Text

Word XML Document

Word 2003 XML Document

Works 6.0-9.0

In the File name box, type a name for the file. Click Save. File will be saved in the desired format.

2.8 How to create a new folder:

When saving a document you are working on in Microsoft Office, you are prompted to enter a name for the new file. After you enter the name of the file, file is saved in the current folder. To move it to another folder or directory, or create a new folder in which to save the file, following instructions are to be followed:

1. Click File and Save as. The Save as dialog box appears.

59

2. Look in the upper-right corner of the Save as dialog box. The folder with a star burst is the button to create a New Folder. Before clicking on the

New Folder icon, look at the directory and drive that is open. If this is the location where you want to create a new folder, then skip to Step 4. If you want to create the new folder in a different directory or drive, then go to Step 3.

3. Consider where you want to create the new folder. On the top of the

Save as dialog box is a Save in box that indicates what folder or directory is currently open. To change that location to another folder or directory, click the down arrow at the end of the Save in box and then choose the new location. You can also click on the Up one level icon, which is depicted in the upper-right portion of the dialog box as a file folder with a blue arrow.

4. Click the New Folder icon button and the New Folder dialog box appears with an open box into which to type the desired name for the new folder. After typing in the new folder name, click OK. The Save as dialog will then display the new folder as the save-as location.

5. Enter the name for the document and then click Save to save the file in the folder.

2.9 Tables and tabs using the tab stops and the

TAB

key:

The

TAB

key, marked with two horizontal arrows, is used to type tables with columns lined up. If variable-pitch characters (as in these notes) are being used, it is essential to use tabs, otherwise the columns (although they may look neat in the document window) will not be lined up when the document is printed.

By default, tab stops are set every 0.5". The faint marks on the lower part of the Ruler indicate the position of these default tab stops. Pressing the

TAB

key makes the insertion point move from tab stop to tab stop. Each time you press the

TAB

key, a tab character is inserted into the text. Tab characters can be deleted in the usual way, using the

BACKSPACE

or

DELETE

key. Try some experiments.

In a table it is

essential

to press

SHIFT

+

ENTER

at the end of each line (apart from the last).

Why use

SHIFT+ENTER?

When

SHIFT

+

ENTER

is pressed, Office starts a new line, but not a new paragraph.

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One of the reasons for pressing

SHIFT

+

ENTER

at the end of a line in a table is that the whole table (not each line separately) will be treated as a paragraph. Office allows you to keep all the lines of one paragraph together, so that the paragraph (in this case a table) will not be split at a page break.

If the non-printing symbols are not visible, ask Office to indicate where

TAB

,

ENTER

and

SHIFT

+

ENTER

were pressed by clicking on the

f

button in the Standard Toolbar.

Office indicates where

TAB

was pressed by means of horizontal arrows, and where

SHIFT

+

ENTER

was pressed by means of bent left-pointing arrows.

Preventing a table from being split:

As already noted, MS-Office automatically divide long pieces of text into pages, and this can result in a table being split. To prevent this:

Select the whole table

Choose the Paragraph command from the Format menu Ensure that the Line and Page Breaks index card is at the front In the Pagination section, click in the Keep lines together box Click on the OK button Try this.

Setting your own tab stops:

To set your own tab stops:

• Click on the lower part of the Ruler (below the dots) in the place where the new tab stop is required

In the Ruler, a L will indicate the position of the new tab stop. Try clicking in the Ruler at 1" and 3.5".

Provided you pressed

SHIFT

+

ENTER

at the end of every line, the columns will move across to obey the new tab stops.

2.10 Bullets and numbering:

Arrange for the references to have bullets as follows:

Select the paragraphs containing the references

Choose the Bullets and Numbering command from the Format menu; the Bullets and

Numbering dialogue box appears, with four "index cards" labelled Bulleted, Numbered,

Outline Numbered and List Styles. Check that the Bulleted "index card" is at the front

Click on one of the types of bullet

Click on the OK button

Arrange for the references to be numbered as follows:

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Select the paragraphs containing the references

Choose the Bullets and Numbering command from the Format menu; the Bullets and

Numbering dialogue box appears

Click on the "tab" of the Numbered "index card" to bring it to the front

Click on the required style of numbered list

Click on the OK button

2.11 Inserting the page number, date or time:

Choose the Header and Footer command from the View menu.

In the Header and Footer Toolbar there are three useful buttons which make it possible to have, as well as text, the following in the header or footer:

Insert Page Number (marked with a # sign)

Insert Date (marked with the numbers 8 and 7)

Insert Time (marked with a clock)

To include any of these in the header or footer:

Move the insertion point to the required position in the line, using the

TAB

key

Click on the appropriate button

Click on the Close button of the Header and Footer Toolbar to return to Normal View

Changing the page numbering:

If a long document such as a dissertation is to be produced, it may be sensible to break it into small files of not more than, say, 15-20 pages each, for ease of handling.

MS-Office automatically starts the page numbering from 1, so it will be necessary to change the first page number of the second and subsequent documents. To do this:

Choose the Page Numbers command from the Insert menu

In the Page Numbers dialogue box, click on the Format button

In the Page Number Format dialogue box, type the number of the first page in the Start at box

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Click on the OK button in the Page Number Format dialogue box

Click on the

Close button

in the Page Numbers dialogue box (not the OK button, because that might insert a new page number at the bottom right of the page)

Use Print Preview to see the effect of this.

Notice that, in the Page Number Format box, you can also change the format of the page numbers,* for example to i ii i i i o r A B C .

A simpler way of inserting page numbers:

Open the file Crystal by choosing that from the File menu.

If only the page number is required, rather than the more complicated headers and footers described above, then a simpler method may be used as follows:

Choose the Page Numbers command from the Insert menu

In the Position section of the Page Numbers dialogue box, click on the V for a drop-down list and then click on the required position for the number (Top of Page or Bottom of

Page)

In the Alignment section of the Page Numbers dialogue box, click on the V for a dropdown list and then click on the required alignment for the number (left, centred, right and so on)

Click on the OK button to confirm your choice

MS-Office will automatically change to Print Layout View so that you can see the effect of this.

To arrange for the first page to be unnumbered (as for the first page of a letter, or first page in a chapter):

Choose the Page Numbers command from the Insert menu

Click on Show number on first page so that the box no longer contains a tick

Click on the OK button

2.12 Using the spelling and grammar checker:

Close this piece of text without saving the changes and then open the file. To check the spelling in a piece of text:

Place the insertion point at the beginning of the text to be checked

Choose the Spelling and Grammar command from the Tools menu

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The Spelling and Grammar dialogue box appears and the first word not recognized by MS-Office is highlighted in the text. There may be a list of suggested alternative spellings.

If the word is correctly spelled:

Click on the Ignore button

If the word is incorrectly spelled, but the correct version appears in the Suggestions list:

Click on the correct version to select it

Click on the Change button

If the word is incorrectly spelled, but the correct version does not appear in the

Suggestions list:

Type the correct version in the Not in Dictionary box

Click on the Change button

MS-Office may also complain about your grammar (not always appropriately). If you agree with the complaint, edit the text in the upper box and then click on the Change button.

If you do not want MS-Office to check grammar for you, simply click on the Check grammar check box so that the tick disappears.

2.13 Indenting:

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There are two types of indents that can be adjusted: paragraphs and bullet points. Each has a separate way of adjusting the indent size. Below are the different ways you can adjust the indentation in Microsoft Word.

First line indent with tab:

You can also access the Bullet and Numbering window by placing your text cursor on a bulleted or numbered line and right-clicking on the Word document. The first line indent can always be created using the Tab key on the keyboard. To change the first line indent size or indent the full paragraph, following steps should be followed:

Adjusting indents using the ruler:

To adjust a paragraph indent size, use the Ruler, which is just below the menu bar and resembles the picture shown below. If this feature is not visible, see our document on how to enable the Ruler. Towards the left side of the Ruler, look for indent markers that resemble an hourglass, like the image shown below.

The top marker (down arrow) controls the first line indent, the middle marker (up arrow) controls the hanging indent, and the bottom market (small box) controls the left indent. To adjust these indents, you can click and drag each marker to the right or left.

Changing indents in the Paragraph window:

Another way to adjust the indents is to view the Paragraph settings. To view this window double-click on the markers in the Ruler, click Format and then Paragraph, or with the cursor in the paragraph right-click and chose Paragraph. As seen below, in the Paragraph window, the

65

left and right indentation, the first line indent, and hanging indent size can all be adjusted. The hanging and first indent line settings are found under Special in the Indentation section.

At the bottom of the Paragraph settings window, you can preview the look of the indent sizes you are setting and make changes accordingly until you get it the way you want.

66

Adjusting the bullet and numbering indentation:

To adjust the indenting for bullet points, place you text cursor in a bulleted or numbered line in Microsoft Word. Then, in the Format menu, click on Bullets and Numbering. In the

Bullets and Numbering window, click on the Customize button on one of the first three tabs, depending on the type of list you are changing the indentation for.

In the next window that opens, you can adjust the indent size for the bullet position and the text position. At the bottom of that window, you can preview how the indentation sizing will look and make changes accordingly until you get it the way you want.

2.14 Mail Merge:

The Mail Merge feature enables you to take information from two documents, one, a Main

Document and two, a Data Source, and combine them into a

67

single document. This feature allows you to write to many different people with the same information which may or may not be modified for each individual. On opening Mail Merge

(Tools/Letters and Mailings/Mailmerge), a Task Pane appears to the right of the document and is visible throughout the entire Mail Merge procedure. The Task Pan will guide you through the mail merge and help you create customized form letters, labels and envelopes. Open a new

The Mail Merge feature takes information from two documents; one, a Main Document and the second, a Data Source, combining them into a single document.

The main document: can be a standard letter, labels, envelopes, e-mail messages or a directory.

The data source: is a file that contains recipients‘ names and addresses, plus any other variable information.

The following is a complete list of the steps required to create a Mail Merge. The Main

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Document is a standard letter.

1. In the Tools menu, point to Letters and Mailings and then click Mail Merge. A Task

Pane appears to the right of the document. There In the Mail Merge Task Pane, click

Letters (if necessary). (When you click an option button, a brief description of that option is displayed in the centre of the Task Pane.)

2. Select Starting Document:

Go to the bottom of the Task Pane and click Starting document You have a choice of three options when starting the document. Use the current document: This is the blank document already on screen.

Start from a template:Use this option if you already have a letter template that you prefer to use, or you can base your document on one of Word‘s mail merge templates.

Start from existing document: Open an existing document that already contains the pre-typed text.

Use the current document for understanding the Mail-merge here.

To continue to the next step, click Select recipients

3. Select Recipients:

The next step is to specify and create the file that contains the recipient‘s names and addresses

(the Data Source) so that Word can attach it to the letter. There are three options for moving forward in this step:

Use an existing list •

Select from Outlook contacts •

Type a new list. •

Under Select recipients, select Type a new list, to create a list of recipients to whom the mail will be sent.

Under Type a new list, click Create to open the New Address List dialog box.

The New Address List box has data fields, any of which can be used in the mail merge, or you can delete them and add your own. (Note: These data fields are the link between your letter and

69

the data source file.)

To delete or add fields, click the Customize button.

To remove a field name, select it and With Title selected, click Delete - a message box appears asking for confirmation. Click Yes to delete the field. Delete the Field Names: Company Name,

Address Line 1, Address Line 2, City, State, PIN Code, Country, Home Phone, Work Phone, and

E-mail Address

Click Add (to add new field names to the list).

In the click Delete, fields must be deleted individually - you cannot select multiple fields. If necessary, use the Move Up and Move Down buttons to arrange the fields in the order you want.

In the box, enter Department.

Click OK to add this field name to the list.

Repeat this action to add the following: Subject, Year_of_Study, Exam_Date (Note that spaces are not allowed in field names.)

Click OK to close the Customize Address List dialog box.

In the New Address List dialog box, enter data as shown.

First Name:Theo, Last Name:Colbin, Department: Physics, Subject: Physics , Year_of_Study: ,

Exam_Date: 12/11/03.

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Click New Entry and enter another two records as shown.

You can view and edit the records by clicking the Next or Previous button. Close, the Save

Address List dialog box appears.

Call the file My_data_source. The data source will be saved as a Microsoft Office Address Lists

71

file type, in the My Data Sources folder.

The Mail Merge Recipients box appears and you have the option to sort or filter the address list.

Click OK to return to Mail Merge. In the Task Pane, you can now see the name of the data source file.

4. Write the standard letter:

Click in Write your letter.

Type the standard text of the letter as below, putting a [tab] between Department, Subject and

Year.

Dear

Department: Subject: Year:

Your examination has been scheduled for . It will take place in the department and you are requested to arrive ten minutes before it starts at 9:30am.

Yours sincerely,

Department Secretary

Enter the fields - add recipient information to your letter.

Place the insertion point where you want to insert the first merge field. The Mail Merge Task

72

Pane lets you choose from the following merge field options: Address Block:, Greeting Line:,

Electronic Postage:, More items...

To access your own fields, click in More Items.

As you select the fields in turn, the Insert Merge field dialog box is opened.

Click Insert then Close.

Again, click in More Items, repeating the above until all your fields are inserted, ensuring that you have the insertion point in the correct place.

When you have finished editing the main document, save and name the file.

To advance to the next step,

Click Preview your letters.

5. Preview Your Letters:

Click the arrow buttons in the Task Pane to preview the letters.

Make any last minute changes to the data source file by clicking Edit recipient list and close the document. To proceed to the final step, click Next: Complete the merge.

6. Complete the Merge:

You are now ready to print the letters and there are two options:

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Print:

Click this option to print the letters. The Merge to Printer box lets you choose which records to send to the printer.

Edit individual letters:

This allows you to personalise individual letters. With this option you get the Merge to New

Document box. Click OK and the letters are merged to a new document, thereby giving you the opportunity to edit each individual letter. You will see that each letter is separated by a section.

When you are ready to print the letters, click Print on the File menu.

Sorting records

Before you print your standard letters, you may want to sort them in a particular way. For example, you might want to print all the letters in alphabetical order by last name. You can do this by sorting the records in the data source by a field in ascending or descending order. By default, the records are sorted in ascending order.

To sort records:

Click the Mail Merge Recipients button to open the Mail Merge Recipients dialog box.

Click in the arrow as shown to display a menu.

Choose (Advanced…) to open the Filter and Sort dialog box.

Activate the Sort Records tab.

From the Sort by list, select Last_Name.

Your list of field names appears. You can sort records according to any of the field names. Next

74

to Sort by, Ascending is selected by default.

Click in Descending.

Click OK to close the Filter and Sort dialog box. In the Mail Merge Recipients dialog box, the records are sorted by Last_Name in descending order.

Click OK. To view all your records, click in the arrows under Preview your letter. Save the document.

Merging addresses into mailing labels:

You can also create mailing labels by using the mail merge feature. This is done by merging data from a data source into a mailing label document. The steps to do so are as follows.

Create a document and open Mail Merge.

Under Select document type, select Labels.

In the next step of the wizard, click Next: Starting document, then Label options to open the

Label Options dialog box.

Specify the printer and label settings in the Label Options dialog box.

Click OK. A sheet of labels with the specified label information is created.

Specify the data source by clicking Browse. Click Next: Select recipients. This opens the Mail

Merge Recipients dialog box.

Close the dialog box and move to the next step in the wizard.

Insert the fields in the document.

Click Update all labels to add the labels to all the divisions in the document.

Click the View Merged Data button.

Preparing mailing labels:

Open a new document.

Choose Tools, Letters and Mailings, Mail Merge and select Labels.

Click in Starting document, choose Label Options under Change Document Layout. Select the label to match your stationery (in this case, select 5159- Address).

75

Click OK to create a sheet of labels with the specified label information.

Click Next: Select recipients.

Under Use an existing list, click Browse to open the Select Data Source dialog box.

Open your file, My_data_source to open the Mail Merge Recipients dialog box.

Click OK to close the dialog box.

The first division is blank. In the other divisions, the field, Next Record appears. Next: Arrange your labels. Arrange your labels, click More items to open the Insert Merge Field dialog box.

Select each appropriate field, putting a space or return between fields as necessary, clicking

Close after each field.

Under Replicate labels, click Save the document as My_label_form.

To insert the fields in all the divisions.

76

Update all labels on the Task Pane.

Viewing the merged labels:

Click on Next - Preview your labels.

This will show how the labels will appear when printed.

Save the document as My mailing labels.

Preview and print labels:

Before printing mailing labels, you can preview them by clicking on the arrow buttons on the

Task Pane, Printing labels

(Choose File, Print.) The Print dialog box appears. Select the printer and click OK to print the document.

2.15 Writing a CD:

To write data on CD, following steps should be followed:

1. Insert a blank, writable CD into the CD recorder. Use one of the following:

Recordable compact disc (CD-R)

The reasons for writing your data on a CD are endless. As more and more computers come standard with a CD-ROM drive, for creating backup copies and to share files with other people, one should write data onto a CD. For example, you might want to write a CD to preserve the digital photographs you took on vacation instead of taking up precious space on your hard drive.

Or you might want to keep a digital record of your house inventory on a CD and store that CD in a safety deposit box. When you copy a Word document to a disc, you don't have to open the file to do so. You can copy the file from its current location to the disc drive. The Word document will remain in its original location from where it is copied.

77

Rewritable compact disc (CD-RW): With rewritable CDs, you can copy data to and erase data from the CD multiple times.

2.

Click Start, and then click My Computer.

3.

Click the files or folders that you want to copy to the CD.

4.

To select more than one file, hold down the CTRL key while you click the files you want.

Then, under File and Folder Tasks, click Copy this file, Copy this folder, or Copy the selected items. If the files are located in My Pictures, under Picture Tasks, click Copy to

CD or Copy all items to CD.

5.

In the Copy Items dialog box, click the CD recording drive, and then click Copy. In My

Computer, double-click the CD recording drive. Windows displays a temporary area where the files are located before they are copied to the CD. Verify that the files and folders that you intend to write to the CD appear under Files Ready to be Written to the

CD. Under CD Writing Tasks, click Write these files to CD. Windows displays the CD

Writing Wizard. Follow the instructions in the wizard. After you copy files or folders to the CD, you can view the CD to confirm that the files have been copied.

78

Unit-3

EXCEL/ SPREAD-SHEET

3.0 Introduction

Of all the computer functions, spreadsheets are the hardest to get to grips with. But a small investment of time and effort will soon pay dividends, because once you have the hang of them, spreadsheets can perform quite complex financial calculations.

Microsoft-Excel or Spreadsheet is a very popular and powerful spreadsheet application. Spreadsheets facilitate the production of lists, tables and charts which means they are much used by those who wish to prepare balance sheets of income and expenditure. They may also be used to

process examination results and to tabulate anything from any record.

You can, for example, set up a spreadsheet to work out the true cost of running your car, including such invisible outlay as depreciation and wear and, tear. All you have to do is 'explain' the task to the program once: it will do all the arithmetic for you, month after month, year on year.

Opening a NEW

spreadsheet:

Microsoft Excel and the spreadsheet tool in Microsoft Works. To open a document in either program, go to the

Start

menu and select

Programs

then

Microsoft Excel

or

Microsoft Works.

If you open Excel, a new blank document will automatically appear on screen. If you open Works, the Works Task Launcher will open. Click on the

Works Tools

tab, then on the

Spreadsheet

button, then on

OK.

79

LOGGING IN AND STARTING:

EXCEL

DESCRIPTION OF THE CELLS

:

The

Excel

window is headed by several bars which you should learn to identify:

1.

The Title Bar

(blue, saying

Microsoft Excel - )

2.

The Menu Bar

(with

File, Edit, View

etc.)

3.

The Standard Toolbar

(with the

New, Open, Save

etc. buttons)

4.

The Formatting Toolbar

(with the

Font, Font Size, Bold

etc. buttons)

5.

The Formula Bar

(with the Name Box on the left, probably containing Al)

The Formula Bar is the only bar with a different name and purpose from the bar in the equivalent position in

MS-Office

.

This bar is particularly important in

Excel

and you should take special note of it.

80

Use the mouse to point (but not click) in the white area above the column labels D,

E, F

etc. After a second or two, a yellow

Screen Tip

tells you that this is the

Formula Bar.

At the bottom of the window there are two more bars associated with

Excel:

6.

The Horizontal Scroll Bar

7.

The Status Bar

Finally, below the Status Bar (which probably says

Ready),

there is the Windows taskbar whose buttons indicate what other windows are open behind the

scenes.

All the facilities of

Excel

can be accessed via menus and dialogue boxes but, by

using the buttons on the two Toolbars, numerous shortcuts are available.

WORKBOOK AND WORKSHEET:

The main part of the screen is called a workbook. This consists of a collection of worksheets, initially called

Sheet 1, Sheet 2 and

Sheet 3.

These names are to the left of the

81

Horizontal Scroll Bar near the bottom of the screen. Each name is on a sheet tab and

Sheet l is on top to begin with. This is the active sheet.

A worksheet consists of a grid of rectangular

cells

which are arranged in rows and columns. The

rows

are numbered downwards starting from

1

and the

columns

have letters starting from

A.

There are grey

column labels

at the top of the worksheet and grey

row labels

along the left-hand edge. Note particularly column label

A

and row label

1.

Initially, cell

Al

is the

active cell.

It is highlighted by an emphasized border and

Al

is noted in the Name Box at the left-hand end of Formula Bar:

Tap the —>-key to move the selection from cell

Al

to cell

Bl.

Cell

Bl

becomes the active cell and this is noted in the Name Box, to the left of the Formula

Bar.

Repeatedly tap the —>-key and attempt to select a cell which is off the

right-hand side of the window. Notice what happens. More columns appear at the right and columns

A, B

and so on disappear at the left.

Note that columns

A

to

Z

are followed by columns

A A

to

AZ.

The final column is

IV.

You see only part of the full worksheet which has

65,536

rows and

256

columns

altogether.

The standard ways of moving round the worksheet include using:

1. The mouse (clicking a cell makes it the active cell).

2.

The arrow keys (with

Ctrl

when appropriate).

3.

The

Page Up

and

Page Down

keys (next to the

Home

and

End

keys).

4. The scroll bars at the right-hand side and at the bottom of the window.

Try these facilities but end with

Ctrl-Home

to make

Al

the active cell.

82

3.1 Uses of Excel Spread Sheet:

Spreadsheets are often used to store financial data. Formulas and functions that are used on this type of data include:

Performing basic mathematical operations such as summing columns and rows of figures.

Finding values such as profit or loss.

Calculating repayment plans for loans or mortgages.

Finding the average, maximum, or minimum values in a specified range of data.

Graphing or charting data to assist users in identifying data trends.

Sorting and filtering data to find specific information.

The information garnered in a spreadsheet can easily be incorporated into electronic presentations, web pages, or printed off in report form.

3.2

F

ORMATTING

:

In

Excel

terminology, the

format category

is, by default, this normally means that a number is shown to as many significant figures as will fit in the cell but there is an overriding rule is that any

leading

or

trailing zeros

are suppressed and an

integer (a whole number) is shown without a decimal point.

In a normal-width cell 3.14159 would be written as 3

.14159

but 00503.80 would be written as 503.8 (without the leading and trailing zeros). If you were to divide 100 by 3 (using the formula =100/3) the recurring decimal result would

be taken to as many places as would fit in the cell.

All the numbers in the square meter column are whole numbers so there are no decimal points. The numbers in the square feet column are taken to two decimal places except where the second decimal place would be a zero when

only one decimal place is shown.

A

DJUSTING THE

C

OLUMN

W

IDTH

:

Click the grey column label B to select the square meter column.

83

Open Format and choose Column ► Width... The Column Width dialogue

box indicates the current column width. A possible value might be 8.43

[characters wide].

Key in 15 to replace the 8.43 (or other value) and click

OK.

The whole column gets much wider and the general appearance certainly hasn't improved. You could experiment with different widths but one useful

option should be explored:

Check that column B is still selected (click the column letter if not).

Open Format and choose Column ► AutoFit Selection.

The AutoFit Selection facility makes a column just a little wider than the widest entry. Very often it is sensible to apply AutoFit Selection to

every

column in use:

Drag from column label A to column label D to select the whole of the first

four columns.

Open Format and choose Column ► AutoFit Selection.

This doesn't quite work as intended. Column A becomes enormously wide to

accommodate the heading in cell Al.

You could put matters right by selecting just column A and specifying a

narrower width but it is worth noting an alternative approach:

Drag diagonally from cell A3 to cell D10. This selects all your entries

except the top heading.

Open Format and choose Column ► AutoFit Selection.

3.3 Range Names In Excel:

There is a number of ways you can name a range of cells.

84

The first one is by using the Name box to the immediate left of the formula bar (see fig. 1).

When the current selected range is already named, the name box will show its name. Otherwise you'll see the address of the active cell in this box. Select the range you want to name and then click in the Name box and type the name. Press Enter to confirm. There is one drawback to this method. When a name already exists, Excel will not apply the name to the selection. Instead

Excel will select the range belonging to the existing definition of the name you typed.

So the Name box can also be used to navigate to an existing name. Just select it from the dropdown list or type it in the box and hit enter.

Fig. 1: Name Box Showing Cell Address

A very fast way to create range names can be used when the headings of a table already represent the names you would like to assign to its rows and/or columns. See the table shown in fig. 2:

Fig. 2: Range of cells with headings

Select the both the tables content and its headers. Then choose Insert, Name, Create from the menu.

You'll see the dialog screen of fig. 3 popup. By selecting the options shown in that screenshot, seven names are defined in one go:

85

Fig. 3: Dialog screen Create Names

Name Refers to: Or

Apples =Sheet1!$B$2:$B$4 The three cells below Apples

Pears =Sheet1!$C$2:$C$4 The three cells below Pears

Bananas =Sheet1!$D$2:$D$4 The three cells below Bananas

Europe =Sheet1!$B$2:$D$2 The three cells to the right of Europe

Asia =Sheet1!$B$3:$D$3 The three cells to the right of Asia

America =Sheet1!$B$4:$D$4 The three cells to the right of America

Turn Over =Sheet1!$B$2:$D$4 All cells in the table, except the headers

The third way to define a name through the user interface is by selecting Insert, Name, Define from the Menu. See fig. 4. This method will be used throughout the rest of this article.

86

Fig. 4: Dialog screen Define Name

3.4 Protecting Cells:

To protect cells following steps should be followed:

Step 1: Select all cells in current worksheet with pressing the Ctrl key and A key together.

Step 2: Right click, and select the Format Cell item from the context menu.

Step 3: In the Format Cells dialog box, uncheck the Locked option under Protection tab, and click OK button. See the following screen shot:

87

Step 4: Select cells and ranges that you want to lock.

Step 5: Right click selected ranges, and select the Format Cell item from the context menu.

Step 6: In the Format Cells dialog box, check the Lock option under Protection tab, and click

OK.

Step 7: Click the Protect Sheet button in the Changes group under Review tab.

88

Step 8: In the Protect Sheet dialog box, enter a password in the blank box under Password to

unprotect sheet: See the following screen shot:

Step 9: Confirm Password dialog box pops up, please reenter the password again.

Step 10: Click OK.

Then it locks and protects only selected cells and ranges in current worksheet, while unselect ranges are editable.

3.5 Sorting:

89

The term

list

is used in

Excel

to describe a labelled series of rows that contain simar data.

The sort feature in Excel allows you to look at the same data in different ways depending upon what information you are after.

Excel allows you to sort by date, sort by text or numbers, sort by multiple columns, or by color.

And, if you like, you can even color code your data.

Types of sorting:

When sorting data, it's important to first decide if you would like the sort to apply to the entire

worksheet or just a cell range.

Sort sheet organizes all of the data in your worksheet by one column. Related information across each row is kept together when the sort is applied. In the example below, the Contact Name column (column A) has been sorted to display the names in alphabetical order.

90

Sort range sorts the data in a range of cells, which can be helpful when working with a sheet that contains several tables. Sorting a range will not affect other content on the worksheet.

To sort a sheet:

In our example, we'll sort a T-shirt order form alphabetically by Last Name (column C).

1. Select a cell in the column you wish to sort by. In our example, we'll select cell C2.

91

2. Select the Data tab on the Ribbon, then click the Ascending command to Sort A to Z, or the Descending command to Sort Z to A. In our example, we'll click the

Ascending command.

3. The worksheet will be sorted by the selected column. In our example, the worksheet is now sorted by last name.

92

To sort a range:

In our example, we'll select a separate table in our T-shirt order form to sort the number of shirts that were ordered on different dates.

1. Select the cell range you wish to sort. In our example, we'll select cell range A13:B17.

93

2. Select the Data tab on the Ribbon, then click the Sort command.

3. The Sort dialog box will appear. Choose the column you wish to sort by. In our example, we want to sort the data by the number of T-shirt orders, so we'll select Orders.

94

4. Decide the sorting order (either ascending or descending). In our example, we'll use

Smallest to Largest.

5. Once you're satisfied with your selection, click OK.

6. The cell range will be sorted by the selected column. In our example, the Orders column will be sorted from lowest to highest. Notice that the other content in the worksheet was not affected by the sort.

95

If your data isn't sorting properly, double-check your cell values to make sure they are entered into the worksheet correctly. Even a small typo could cause problems when sorting a large worksheet. In the example below, we forgot to include a hyphen in cell A18, causing our sort to be slightly inaccurate.

96

Custom sorting:

Sometimes you may find that the default sorting options can't sort data in the order you need.

Fortunately, Excel allows you to create a custom list to define your own sorting order.

To create a custom sort:

In our example below, we want to sort the worksheet by T-Shirt Size (column D). A regular sort would organize the sizes alphabetically, which would be incorrect. Instead, we'll create a custom list to sort from smallest to largest.

1. Select a cell in the column you wish to sort by. In our example, we'll select cell D2.

2. Select the Data tab, then click the Sort command.

97

3. The Sort dialog box will appear. Select the column you want to sort by, then choose

Custom List... from the Order field. In our example, we will choose to sort by T-Shirt

Size.

4. The Custom Lists dialog box will appear. Select NEW LIST from the Custom Lists: box.

5. Type the items in the desired custom order in the List entries: box. In our example, we want to sort our data by T-shirt size from smallest to largest, so we'll type Small,

Medium, Large, and X-Large, pressing Enter on the keyboard after each item.

98

6. Click Add to save the new sort order. The new list will be added to the Custom lists: box. Make sure the new list is selected, then click OK.

99

7. The Custom Lists dialog box will close. Click OK in the Sort dialog box to perform the custom sort.

8. The worksheet will be sorted by the custom order. In our example, the worksheet is now organized by T-shirt size from smallest to largest.

100

To sort by cell formatting:

You can also choose to sort your worksheet by formatting rather than cell content. This can be especially helpful if you add color coding to certain cells. In our example below, we'll sort by

cell color to quickly see which T-shirt orders have outstanding payments.

1. Select a cell in the column you wish to sort by. In our example, we'll select cell E2.

2. Select the Data tab, then click the Sort command.

3. The Sort dialog box will appear. Select the column you wish to sort by, then decide whether you'll sort by Cell Color, Font Color, or Cell Icon from the Sort On field. In our example, we'll sort by Payment Method (column E) and Cell Color.

101

4. Choose a color to sort by from the Order field. In our example, we'll choose light red.

5. Click OK. In our example, the worksheet is now sorted by cell color, with the light red cells on top. This allows us to see which orders still have outstanding payments.

102

Sorting levels

If you need more control over how your data is sorted, you can add multiple levels to any sort.

This allows you to sort your data by more than one column.

To add a level:

In our example below, we'll sort the worksheet by Homeroom Number (column A), then by

Last Name (column C).

1. Select a cell in the column you wish to sort by. In our example, we'll select cell A2.

103

2. Click the Data tab, then select the Sort command.

3. The Sort dialog box will appear. Select the first column you wish to sort by. In this example, we will sort by Homeroom # (column A).

4. Click Add Level to add another column to sort by.

5. Select the next column you wish to sort by, then click OK. In our example, we'll sort by

Last Name (column C).

104

6. The worksheet will be sorted according to the selected order. In our example, the homeroom numbers are sorted numerically. Within each homeroom, students are sorted alphabetically by last name.

If you need to change the order of a multilevel sort, it's easy to control which column is sorted first. Simply select the desired column, then click the Move Up or Move Down arrow to adjust its priority.

105

Defining range In Microsoft Excel, you may have a named range that must be extended to include new information. This article describes a method to create a dynamic defined name.

3.6

C

HARTING

D

ATA

S

ERIES AND

C

ATEGORIES

:

There are numerous facilities in

Excel

for preparing charts and graphs. Charts can be created,

embedded

in a worksheet or as a separate

chart sheet.

Excel Graph Types

There are many graphs or charts available in spreadsheet programs such as Excel and each has its own uses. The list below leads to information about the different Excel graphs and their uses.

Bar Graphs

Line Graphs

Scatter Plot Graphs

Pie Charts

Bar Graphs

106

Bar graphs are one of the most common types of graph used to display data. Sometimes known as "column charts", bar graphs are most often used to show amounts or the number of times a value occurs.

The amounts are displayed using a vertical bar or rectangle. The taller the bar, the greater number of times the value occurs.

For example, for a school class you can use a bar graph to show and compare the number of students with different hair colors. The more students with a particular hair color, the taller the bar for that color will be in the graph.

Bar graphs make it easy to see the differences in the data being compared.

Line Graphs

Line graphs are often used to plot changes in data over time, such as monthly temperature changes or daily changes in stock market prices.

107

They can also be used to plot data recorded from scientific experiments, such as how a chemical reacts to changing temperature or atmospheric pressure.

Similar to most other graphs, line graphs have a vertical axis and a horizontal axis. If you are plotting changes in data over time, time is plotted along the horizontal or x-axis and your other data, such as rainfall amounts is plotted as individual points along the vertical or y-axis.

When the individual data points are connected by lines, they clearly show changes in your data - such as how a chemical changes with changing atmospheric pressure. You can use these changes to predict future results.

Scatter Plot Graphs

Scatter plot graphs are used to show trends in data. They are especially useful when you have a large number of data points. Like line graphs, they can be used to plot data recorded from scientific experiments, such as how a chemical reacts to changing temperature or atmospheric pressure.

108

Whereas line graphs connect the dots or points of data to show every change, with a scatter plot you draw a "best fit"line. The data points are scattered about the line. The closer the data points are to the line the stronger the correlation or affect one variable has on the other.

If the best fit line increases from left to right, the scatter plot shows a positive correlation in the data. If the line decreases from left to right, there is a negative correlation in the data

Excel Pie Charts

Pie charts, or circle graphs as they are sometimes known, are a little different from the other three types of graphs discussed.

109

For one, pie charts do not use horizontal and vertical axes to plot points like the others. They also differ in that they are used to chart only one variable at a time. As a result, it can only be used to show percentages.

The circle of pie charts represents 100%. The circle is subdivided into slices representing data values. The size of each slice shows what part of the 100% it represents.

Pie charts can be used anytime you want to show what percent a particular item represents of a data series such as:

A baseball player's batting average can be shown with a pie chart as it represents the percentage of hits when compared to his total number of at bats for a season.

A company's profits for each month can be shown with a pie chart as a percentage of the year's total profits.

C

HANGING THE

S

IZE OF THE

C

HART

:

The outermost boundary of the chart has eight

handles,

four at the corners and four in the middles of the sides. These handles indicate that the chart is selected.

A

selected chart can be deleted by pressing the

Delete

-key. If your

chart is completely wrong delete it and start again.

The handles on the chart boundary can be dragged so that the edges and

corners can be moved:

Click a cell in the worksheet outside the chart. The handles disappear as

the chart ceases to be selected and the newly active cell is selected

instead.

Click

just

inside the chart. The chart is again selected. Ensure that the bottom edge of the chart is exposed; use the Vertical Scroll Bar if

necessary.

110

Point at a handle and notice how the pointer becomes a double-headed

arrow.

Drag the different handles in turn so that the border exactly fills all the

cells in the range

E13

to

J26.

M

OVING THE

D

ATA AND THE

C

HART

:

You should now have a reasonably tidy chart but the worksheet as a whole would look better if the data were moved one column to the right and the chart moved underneath the data. The data occupy four columns and the chart

occupies six columns:

Click cell A3 to select it (and unselect the chart).

Open Insert and choose Columns. Everything moves right one column

including the chart.

Click anywhere in the chart. This selects the chart and you can then...

Drag the chart as far to the left as it will go.

By using the drag handles, arrange for the chart border to fill all the cells

in the range A13 to F26.

3.7

U

SING

F

ORMULAE

Suppose you are putting length in meters in first column, breadth in second column and now you wish to add a third column giving the areas in square feet. Take one square meter to be 10.76 square feet. The first new entry will be 10.76 x length x breadth in cell CI. It is time to use a spreadsheet

formula:

• Make cell CI the active cell and key in

=10.76 *A1*B1

(the equals sign is essential).

Click the Enter box (with the tick) to confirm. An

Excel

formula is

always introduced by an equals sign.

In simple cases, formulae consist of numbers, cells

111

and arithmetic operators (principally +, —, * and /, the last two being for multiplication and division).

A

RRAY

R

ANGE

F

ILL

D

OWN

Up until now only one cell, the active cell, has been selected at a time. By dragging the mouse, you can highlight an

array range

so that a group of cells is selected at once. Certain operations can be performed on the group taken as

a whole:

• Drag the mouse from cell CI to cell

C6.

This selects the range

C1: C6

(as it would normally be written). Check that a common border encloses the array of six cells (although only cells

C2

to

C6

are

shaded).

Open the

Edit

menu and click

Fill.

In the sub-menu click

Down.

The formula in cell

CI

(the 'white' cell) is copied

into the other selected cells.

Make cell

C2

the active cell and note, in the Formula Bar, that the formula in this cell is now

=10.76*A2*B2.

Check that the formula in cell

C3

is now

=10.76*A3*B3

and so on.

Most, but not all, values are taken to two decimal places. This inconsistency

makes the new column a little untidy and will be attended to shortly.

The

Fill ► Down

facility and a companion facility

Fill ► Right,

which works on a horizontal array of selected cells, are powerful features when setting up a

spreadsheet.

T

HE

SUM F

UNCTION

:

Next, incorporate some totals. First:

• Make cell

A9

the active cell and key in

Totals

112

Although in cell

B9

you could now key in

=B2+B3+B4+B5+B6+B7

as the formula to add

up the six areas in the second column, there is a better way...

• Make cell

B9

the active cell and key in

=SUM(B2:B7)

and click the

Enter box (with the tick) to confirm.

There are scores of functions built into

Excel and

SUM is one of them; it totals the values in the array range supplied in brackets.

An item in brackets after the name of a function is called an

argument

of the function. Here the argument

B2:B7

designates the range of cells

B2

to

B7

inclusive.

Although you could now make cell

C9

the active cell and key in

=SUM(C2:C7),

it is easier to use the

Fill Right

facility as follows:

Drag the mouse from cell

B9

to cell

C9

to select these two cells.

Open the

Edit

menu and choose

Fill ► Right.

Convert the three entries in row

9

to bold fount.

When a formula incorporates a function, the

Insert Function

button, marked f x

and found to the left of the Formula Bar, is sometimes useful. In the special case of the

SUM

function, it is better still to use the

AutoSum

button, marked with a E-sign

in the Standard Toolbar. These buttons will be discussed later.

P

ERCENTAGES

, R

ELATIVE AND

A

BSOLUTE

R

EFERENCES AND THE

$ P

REFIX

:

Suppose you now wish to add a fourth column showing each of the six areas

as a percentage of the total.

• Key in the formula

=B2/B9.

Click the Enter box. The result is 0.15 which

• Open

Format

and choose

Cells...

The dialogue box indicates that the

Category

is

General.

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• Make cell

D2

the active cell.

• Click the

Percentage

category and again check that the number of

Decimal places

is shown as

2.

Click OK. The value in cell

D2

changes to

15.00%.

Check that

D2

is the active cell. You could key in the whole of the revised formula afresh, but since it is only one character different a shortcut is

advised...

Click in the Formula Bar between the

B

and the

9

of

B9

and then key in $.

The formula changes to

=B2/B$9

as required. Click the Enter box. The result in

D2

is

15.00%

as before.

Drag the mouse from cell

D2

to cell

D7

to select the array of six cells again.

Open Edit and choose Fill ► Down. This time the entries are sensible percentages.

Make cell

D3

the active cell. The formula (look at the Formula Bar) is

=B3/B$9

and you will find that the formula in cell

D4

is

=B4/B$9.

The $ really does mean that the

9

Sticks at

9.

You could have had a second $ and included

$B$9

in the formula. This extra $ forces the

B

to Stick to being a

B

but since you are filling down a column, the

B

won't change anyway. If you were filling a row using

Fill ► Right

then prefixing the

B

would be essential.

3.8

S

AVING YOUR DOCUMENT

:

Whenever you prepare a worksheet it is advisable to save it in a file soon after starting and to keep saving at frequent intervals thereafter. Open the

File

menu and choose

Save As

so that the

Save As

dialogue box appears. Type the

File name(Book1)

into the

File name

box.

Click

Save.

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This saves the file. The

Bookl appears

in the Title Bar

.

As a matter of note, the file name extension

.xls

indicates an

Excel

file.

3.9 Printcomments:

If your worksheet contains comments like the one shown here, you can print them, either as they appear on the sheet or at the end of the sheet.

1. Click the worksheet that contains the comments that you want to print.

2. To print the comments in place on the worksheet, display them by doing one of the following:

To display an individual comment, right-click the cell containing the comment, and then click Show/Hide Comments on the shortcut menu.

To display all comments in the worksheet, on the Review tab, in the Comments group, click Show All Comments.

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If necessary, you can move and resize any overlapping comments. To do this, click the border of the comment box so that handles appear.

To move the comment, drag the border of the comment box. To change the size, drag the handles on the sides and corners of the box.

3. On the Page Layout tab, in the Page Setup group, click the dialog box launcher to open the Page Setup dialog box.

4. Click the Sheet tab.

5. In the Comments box, click As displayed on sheet or At end of sheet.

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6. At the bottom of the dialog box, click Print.

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Unit-4

PowerPoint Presentation

4.0 Introduction:

PowerPoint is a complete presentation graphics package. It gives you everything you need to produce a professional-looking presentation. PowerPoint offers word processing, outlining, drawing, graphing, and presentation management tools- all designed to be easy to use and learn.

Microsoft PowerPoint is a presentation software package. PowerPoint users create and organize slides on a computer, to be printed on paper or acetate transparencies, projected directly from the computer or shared via the Internet. Users can create graphs and diagrams to which they may then add graphics and text. It also allows users to incorporate animation, audio and video elements. As well as presentations, PowerPoint can be used to make games, tutorials, animations and posters.

4.1 Features of PowerPoint:

PowerPoint uses a graphical approach to presentations in the form of slide shows that accompany the oral delivery of the topic. This program is widely used in business and classrooms and is an effective tool when used for training purposes.

1. PowerPoint is a quick and easy way to organize ideas and information, but it can encourage the creation of presentations that lack substance.

2. PowerPoint is regarded as the most useful, accessible way to create and present visual aids; others believe it has its own mind-set which forces presenters to spend countless hours thinking in PowerPoint and developing slides.

3. Easy to create colourful, attractive designs using the standard templates and themes; easy to modify compared to other visual aids, such as charts, and easy to drag and drop slides to reorder presentation.

4. Easy to present and maintain eye contact with a large audience by simply advancing the slides with a keystroke, eliminating the need for handouts to follow the message.

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5. PowerPoint is one of the simplest computer programs to learn. It is the number 1 program used worldwide for presentations. Anyone can create stunning presentations that look like they were designed by a professional.

6. PowerPoint presentations can be made into photo albums, complete with music or narrations, to distribute on CDs or DVDs. If you are in the sales field, it involves just a few simple clicks to add an illustrative chart of data or an organizational chart of your company's structure. Make your presentation into a web page for emailing purposes or as a promotion displayed on your company's website.

7. It is easy to customize presentations with your company logo and to dazzle your audience by using one of the many design templates that come with the programs. Many more free add-ins and templates are available online from Microsoft and a host of other websites. In addition to an on screen slide show, PowerPoint has printing options that allow the presenter to provide handouts and outlines for the audience as well as notes pages for the speaker to refer to during the presentation.

8. The main features of Microsoft PowerPoint include having advanced cropping tool and artistic filters such as blur, paintbrush as well as watercolour. These features help in adding visual impact to the presentations.

4.2 Uses of Power Point Presentation:

When you create a presentation using PowerPoint, the presentation is made up of a series of slides. The slides that you create using PowerPoint can also be presented as overhead transparencies or 35mm slides.

In addition to slides, you can print audience handouts, outlines, and speaker's notes.

You can format all the slides in a presentation using the powerful Slide Master which will be covered in the tutorial.

You can keep your entire presentation in a single file- all your slides, speaker's notes, and audience handouts.

You can import what you have created in other Microsoft products, such as Word and

Excel into any of your slides. PowerPoint can go just about anywhere the presenter or

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audience goes. PowerPoint files are portable, making them easy to share, edit and view.

A presentation can be emailed, saved directly to a computer, carried on a flash drive or uploaded to a Web site. With PowerPoint, the speaker can also record their presentation and save it for future use so that employers, students or other audiences can still view it without having to be there live. PowerPoint includes a number of features that allow presenters to better engage the audience.

Use PowerPoint to add video, photos, animations and slide transitions. These elements can help grab attention and break up mundane lectures or speeches. Video and photos can be directly embedded into presentations as well as edited directly through PowerPoint.

No additional software is needed. PowerPoint also allows the presenter to add animations that can accentuate or highlight important points. Slide transitions work to move the presentation from one topic to the next.

4.3 Toolbar:

Toolbar is just below the Menubar. Toolbar is large in number. PowerPoint includes 13 toolbars including commonly used ones such as Standard, Formatting, Table and Borders,

Drawing, Animation Effects, Pictures and E-mail. Toolbars include important components for developing a presentation. A toolbar is an onscreen bar which contains shortcut buttons. These allow easy access to frequently used commands. You can easily get to the toolbars you need by telling PowerPoint which ones to display. You can pick and choose which toolbars are visible, and once you know how to turn toolbars on and off, you can always get to the toolbar you need.

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You can also right-click your mouse anywhere in a toolbar area and the list of

PowerPoint toolbars will appear. From here you can turn toolbars on or off.

Moving and Changing the Toolbars

You can reposition toolbars on the presentation you are working on. You can also resize toolbars so that all or only a few of the buttons contained in them are visible.

Each toolbar has four vertical dots that help you move them to a fixed position on the screen or to floating positions on the screen. To move a toolbar, click the four dots that are found on the left end of each toolbar.

Note that when you choose to view a toolbar, it appears in the position in which it was most recently used. In the Toolbars list, click the toolbars you want to display. Click Close, and the toolbars you selected appear on the workspace.

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Creating Your Own Toolbar: You can create your own customized toolbar. Right click any toolbar and hit Customize. In the Customize dialog box, select the toolbars tab and click New.

Name the toolbar and allocate a template.

4.4 Creating Presentation:

To create presentation by using template, follow these steps:

1. Start Power Point.

2. Select 'Design Template' option and click on 'OK' button. 'New Presentation' dialog box will open.

3. ‗New Presentation' dialog box has three options and in each option a list is available. Select any desired option and click on OK button. 'New Slide' dialog box will open.

4. Select desired option and click on 'OK' button. For example, if we select 'Blank Presentation', then we will see the blank slide.

To use slide master, follow these steps:

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1. Create blank presentation.

2.

3.

Click on View' menu. A drop down list will open.

Click on ‗Master' option. A list will open.

4. Click on 'Slide Master' option. As soon as we do this, a slide will appear before us. View your slideshow. To view your final product, you can either click "Slide Show" in the top toolbar or select "Slide Show > View Slide Show" in the main menu.

4.5 Slide Show

A slide show can present and illustrate an event in history, or explain a geometric proof in math. It can illuminate an oral book report, or report the results of a science experiment. Teachers use slide shows as backdrops to their lectures, students use them to deliver reports, and schools use them to show the community what they are doing. A slide show can be a valuable tool for teaching, sharing and learning.

The best way to learn this lesson is to construct your own slide show as you read it. To do this, you'll need a collection of images that can be arranged to tell a story. Once you have the images you need, save them in a folder and get ready to construct your slide show. Make sure all of your images have been saved in the right size and resolution for the screen.

Setting Up a Slide

Open PowerPoint

When you launch the PowerPoint program, it may ask you what kind of document you want to create.

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2. You can choose the wizard tool, a template, or a blank presentation. Choose template. Click

OK.

3. Choose the Blends template

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4 The New Slide layout screen appears. You can select from a variety predesigned layouts. Choose Title Slide Click OK.

5 Click in the Title Box.

6 You can choose different fonts by selecting Font from the Format menu or by pulling down on fonts in the Formatting Bar. You can also select the size and style. TIP:

By using the Formatting Bar, you will be able to see the font style.

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7 Choose a font, size, color and style. Type your title. For this workshop, type

World Travel. You can also add a subtitle. Type Sights and Sounds.

Inserting a Picture

1. Click on New Slide in the Common Tasks window or New Slide from the Insert menu. The short cut is Ctrl+M. TIP: Sometimes this window gets hidden. Knowing the short cut will save you a lot of frustration trying to figure out how to make a new slide or how to get the Common

Task Window to display again.

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2. Choose the Clip Art and Text slide.

1 Insert clip art on your slide by double clicking on the icon or selecting picture from clip art in the Insert menu.

2 Choose travel and then the Leaning Tower from the clip art gallery.

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3

Then, type the title: Leaning Tower of Pisa.

The clip art is automatically inserted in the box. Choose the font, size, and style.

4 Notice in the text box (see screen shot in Step #5) that there is a bullet. This might be fine for listing items, but when you want to type a paragraph, this feature can be annoying. To eliminate bullets, click on the text box. Choose Bullets and Numbering from the Format menu. Click on None and then OK.

5 Type the following in the text box. Be sure to hit enter at the end of each line so the text will line up on the left. After the Leaning Tower of Pisa is shored up, workers say it will lean 19 feet. Type Leaning Tower of Pisa in the Title box.

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Inserting a Sound File

1 Click on New Slide in the Common Tasks window or New Slide from the Insert menu. The short cut is Ctrl+M. TIP: Sometimes this window gets hidden. Knowing the short cut will save you a lot of frustration trying to figure out how to make a new slide or how to get the Common Task Window to display again.

2 Select the Two Column Text Slide.

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3 Add a sound by selecting Movies and Sounds then Sound from Gallery in the

Insert menu.

4. Click on Music.

5 Right click on CARB_1 and select insert. Close the window.

Choose whether or not you want the sound to play automatically or when you 6 click it. You can further customize the order in which objects are played or displayed on your slide by going to custom animation under the Slide Show Menu. You will learn more about custom animation when you insert a movie.

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Inserting a Movie

1 Click on New Slide in the Common Tasks window or New Slide from the Insert menu. The short cut is Ctrl+M. TIP: Sometimes this window gets hidden. Knowing the short cut will save you a lot of frustration trying to figure out how to make a new slide or how to get the Common Task Window to display again.

2 Select the Title Only Slide.

3 To insert a movie select Movies and Sounds from the Insert menu and choose

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Movies from Gallery.

4 slide show.

Right click on the image and select insert. Close the window and return to the

5 In order for the animation to play, you must set the controls for how it will be played. Highlight the movie. Select Custom Animation from the Slide Show menu.

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Check the box next to your movie object. Then, choose the effects you want the movie to exhibit such as flying in from the left before it is played. Finally, set the order in which items on your slide will be displayed and whether or not they will appear automatically or on a mouse click.

Transitions

Transitions between slides will make the show look more professional. The transition you choose will precede the slide.

1

2

Go to your first slide, then select Slide Transition from the Slide Show menu.

Choose the effect and speed you want for the transition. Choose whether or not you want to advance each slide with the mouse or automatically. You can also have a sound effect between slides. Then, click Apply for the current slide or Apply to All for every slide.

Saving the File

1 Save your file often. Select Save As from the File menu. Pull down on the arrow and choose Presentation as the file type (ppt). Name the file and click on Save.

2 To save it as a slide show, select Save As from the File menu. Pull down on the

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arrow and choose PowerPoint Show as the file type (pps). Name the file and click on

Save.

Viewing the Slide Show

Select View Show from the Slide Show menu.

4.6 Saving slide:

1. Display the slide you want to save.

2. On the File menu, click Save As. In the File name box, type a name for your PowerPoint presentation, and then select the graphics format you want, click Save

3. Do one of the following:

If you want to save only the current slide select Current Slide Only.

If you want to save every slide in a presentation select Every Slide.

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Note: By default, PowerPoint 2010 saves files in the PowerPoint Presentation (.pptx) file format. To save your presentation in a format other than .pptx, click the Save as type list, and then select the file format that you want.

4.7 Delete a slide:

To delete the slide, follow these steps:

1. Select desired slide.

2. Press Delete key on keyboard.

As soon as we do this, Power Point will ask us for deleting the slide. Now click the Ok button, desired slide will be deleted.

4.8 Hide a Slide in PowerPoint Presentation:

If there is a slide that you need in your presentation, but you do not want it to appear in the slide show, you can hide the slide. This is particularly useful when you have added slides to a presentation that provide different levels of detail on the subject matter, perhaps for different audiences. You can mark these slides as hidden so that they are not displayed in your main slide show, but you can still access them if you need to. For example, a member of your audience might ask you to explain an item in more detail. In that case, you can reveal the hidden slides that contain those details. When you hide a slide, the slide remains in the file even though it is

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hidden when you run the presentation in Slide Show view. You can switch the Hide Slide option on and off individually for any slide in the presentation.

If you want to hide a slide to later go back to it after by a hyper linked button on another slide, then few quick easy steps are there in PowerPoint Presentation to do so:

1. Open up PowerPoint and a couple of slides.

2. On the Slides tab in normal view, select the slide you want to hide/ not show up while moving through your presentation, then go up to the menu bar and click on "Slide Show".

3. Scroll down the drop down menu to "Hide Slide" and click it or you can just right click and click on "Hide Slide" on the quick menu. The hidden slide icon appears with the slide number inside, next to the slide you have hidden.

136

Create a slide show containing four slides. Leave the first slide white, but format the backgrounds of the remaining slides to be red, blue, and yellow respectively by right clicking each slide thumbnail, choosing FormatBackground from the options, and changing background colours accordingly (Following Figure).

For example we will hide Red and Blue Slides. To hide red and blue slides i.e. slides 2 and 3, select the slide thumbnails and then click the Hide Slide button on the Ribbon‘s Slide Show tab, or right click the selected slide thumbnails and choose Hide Slide from the options (Following

Figure) .

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There are two Methods for Hiding Slides:

When a slide is hidden, its slide number displays with a dashed line and the slide thumbnail displays lighter (Following Figure). At any time, you can unhide a slide by repeating the steps just described.

138

Slide Thumbnails 2 and 3 Display with a Line when Hidden

Next, click the slide 1 thumbnail to select slide 1. Let‘s start the slide show and scroll to see what happens. Notice that PowerPoint skips the red and blue slides entirely and immediately displays the yellow slide instead.

If you are in Slide Show view and you decide that you want to show a slide that you previously hid, right-click the slide that you want to show, and then click Hide Slide.

4.9 Embedding Multimedia:

When utilizing multimedia files such as sound or movies in PowerPoint, PowerPoint can either embed them fully in the PowerPoint file simply create an icon or insert a ―poster frame,‖ and then when it‘s necessary to play the sound or movie, PowerPoint locates the sound or movie file and plays it.

For embedding multimedia following steps has to be followed:

1. Create a new PowerPoint presentation.

2. Navigate to the slide into which you would like to embed the video clip.

3. Select ―Insert‖ → ―Movie…‖ from the menu.

4. Select the video file you want to embed.

5. PowerPoint will ask whether you want the video to begin playing as soon as the slide is shown in presentation mode.

Otherwise only the first frame of the film will appear, and playback will begin when the video is clicked.

6. The first frame of the video will appear on slide stage with a video playback icon superimposed on the lower

The video can be moved and resized just like a picture. left corner.

7. Make sure to save your presentation!

8. See ―Taking Your Presentations With You‖ below if you will not be showing your presentation on the same computer on which it was created.

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UNIT – 5 ACCESS/WORKSHEET

5.1 Introduction

5.2 What is Database?

5.2.1 Database

5.2.2 Data Base Management System

5.3 Access Database

5.4 Relational Database Management System

5.4.1 Advantages

5.4.2 Disadvantages

5.5 Devising Tables and Relationships

Let Us Sum Up (Summary)

Answers

140

5.1 INTRODUCTION

Microsoft Access, also known as Microsoft Office Access, is a database management system from Microsoft that combines the relational Microsoft Jet Database Engine with a graphical user interface and software-development tools. It is a member of the Microsoft

Office suite of applications, included in the Professional and higher editions or sold separately.

Microsoft Access stores data in its own format based on the Access Jet Database Engine. It can also import or link directly to data stored in other applications and databases

Software developers and data architects can use Microsoft Access to develop application software , and " power users " can use it to build software applications.

A worksheet is a sheet of paper, or on a computer, on which problems are worked

A worksheet generator is a software program that generates problems, particularly in mathematics or numeracy . Such software is often used by teachers to make classroom materials and tests.

141

5.2 WHAT IS DATABASE

Learning Objective :-

After studying this sub unit you would be able to – viii. Define what is database ix. Explain database management system

5.2.1 DATABASE

A database is a tool for collecting and organizing information. Databases can store information about people, products, orders, or anything else. Many databases start as a list in a wordprocessing program or spreadsheet. As the list grows bigger, redundancies and inconsistencies begin to appear in the data. The data becomes hard to understand in list form, and there are limited ways of searching or pulling subsets of data out for review. Once these problems start to appear, it's a good idea to transfer the data to a database created by a database management system (DBMS), such as Access 2013.

A computerized database is a container of objects. One database can contain more than one table.

For example, an inventory tracking system that uses three tables is not three databases, but one database that contains three tables. Unless it has been specifically designed to use data or code from another source, an Access database stores its tables in a single file, along with other objects, such as forms, reports, macros, and modules. Databases created in the Access 2007 format

(which is also used by Access 2013 and Access 2010) have the file extension .accdb, and databases created in earlier Access formats have the file extension .mdb. You can use Access

2013, Access 2010, or Access 2007 to create files in earlier file formats (for example, Access

2000 and Access 2002-2003).

5.2.2. DATA BASE MANAGEMENT SYSTEM

A database management system (DBMS) is a collection of programs that enables you to store, modify, and extract information from a database. There are many different types of DBMSs,

142

ranging from small systems that run on personal computers to huge systems that run on mainframes. The following are examples of database applications:

Computerized library systems

Automated teller machines

Flight reservation systems

Computerized parts inventory systems

From a technical standpoint, DBMSs can differ widely. The terms relational, network, flat, and hierarchical all refer to the way a DBMS organizes information internally. The internal organization can affect how quickly and flexibly you can extract information.

Requests for information from a database are made in the form of a query, which is a stylized question. For example, the query

SELECT ALL WHERE NAME = "SMITH" AND AGE > 35 requests all records in which the NAME field is SMITH and the AGE field is greater than 35.

The set of rules for constructing queries is known as a query language. Different

DBMSs support different query languages, although there is a semi-standardized query language called SQL (structured query language). Sophisticated languages for managing database systems are called fourth-generation languages, or 4GLsfor short.

The information from a database can be presented in a variety of formats . Most DBMSs include a report writer program that enables you to output data in the form of a report . Many DBMSs also include a graphics component that enables you to output information in the form of graphs and charts.

Check your progress – 1

Fill in the blanks:

a) A ……………….. is a tool for collecting and organizing information.

b) A computerized database is a container of ………………...

c) A …………………………. is a collection of programs

d) ………………………is a semi-standardized query language.

e) Sophisticated languages for managing database systems are called …………………..

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5.3 ACCESS DATABASE

Learning Objective :-

After studying this sub unit you would be able to – i. Explain access database ii. Describe its parts

The database component of MS Office is designed to act as an "intelligent"1 electronic filing cabinet. Like a manual filing cabinet, it enables you to

• collect sets of related data and keep the data organized;

• update the data once you've collected them, by adding or deleting records and by changing existing records;

An electronic filing cabinet such as a database allows you also to easily and quickly use the data-

-sort them, create reports, merge the data with other documents, and so forth.

Microsoft Access:

Access is an object-oriented relational database management system.

Using Access, you can:

Add new data to a database, such as a new item in an inventory

Edit existing data in the database, such as changing the current location of an item

Delete information, perhaps if an item is sold or discarded

Organize and view the data in different ways

Share the data with others via reports, e-mail messages, an intranet , or the Internet

Access Database Files

You can use Access to manage all of your information in one file. Within an Access database file, you can use:

Tables to store your data.

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Queries to find and retrieve just the data that you want.

Forms to view, add, and update data in tables.

Reports to analyze or print data in a specific layout.

Store data once in one table, but view it from multiple locations. When you update the data, it's automatically updated everywhere it appears.

Retrieve data by using a query.

View or enter data by using a form.

Display or print data by using a report.

The Parts of an Access Database:

The parts of a typical Access database are:

Tables

Forms

Reports

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Queries

Macros

Modules

Tables

A database table is similar in appearance to a spreadsheet, in that data is stored in rows and columns. As a result, it is usually quite easy to import a spreadsheet into a database table. The main difference between storing your data in a spreadsheet and storing it in a database is in how the data is organized.

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To get the most flexibility out of a database, the data needs to be organized into tables so that redundancies don't occur. For example, if you're storing information about employees, each employee should only need to be entered once in a table that is set up just to hold employee data.

Data about products will be stored in its own table, and data about branch offices will be stored in another table. This process is called normalization.

Each row in a table is referred to as a record. Records are where the individual pieces of information are stored. Each record consists of one or more fields. Fields correspond to the columns in the table. For example, you might have a table named "Employees" where each record (row) contains information about a different employee, and each field (column) contains a different type of information, such as first name, last name, address, and so on. Fields must be designated as a certain data type, whether it's text, date or time, number, or some other type.

Another way to describe records and fields is to visualize a library's old-style card catalog. Each card in the cabinet corresponds to a record in the database. Each piece of information on an individual card (author, title, and so on) corresponds to a field in the database.

Forms

Forms allow you to create a user interface in which you can enter and edit your data. Forms often contain command buttons and other controls that perform various tasks. You can create a database without using forms by simply editing your data in the table datasheets. However, most database users prefer to use forms for viewing, entering, and editing data in the tables.

You can program command buttons to determine which data appears on the form, open other forms or reports, or perform a variety of other tasks. For example, you might have a form named

"Customer Form" in which you work with customer data. The customer form might have a button which opens an order form where you can enter a new order for that customer.

Forms also allow you to control how other users interact with the data in the database. For example, you can create a form that shows only certain fields and allows only certain operations to be performed. This helps protect data and to ensure that the data is entered properly.

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Reports

Reports are what you use to format, summarize and present data. A report usually answers a specific question, such as "How much money did we receive from each customer this year?" or

"What cities are our customers located in?" Each report can be formatted to present the information in the most readable way possible.

A report can be run at any time, and will always reflect the current data in the database. Reports are generally formatted to be printed out, but they can also be viewed on the screen, exported to another program, or sent as an attachment to an e-mail message.

Queries

Queries can perform many different functions in a database. Their most common function is to retrieve specific data from the tables. The data you want to see is usually spread across several tables, and queries allow you to view it in a single datasheet. Also, since you usually don't want to see all the records at once, queries let you add criteria to "filter" the data down to just the records you want.

Certain queries are "updateable," meaning you can edit the data in the underlying tables via the query datasheet. If you are working in an updateable query, remember that your changes are actually being made in the tables, not just in the query datasheet.

Queries come in two basic varieties: select queries and action queries. A select query simply retrieves the data and makes it available for use. You can view the results of the query on the screen, print it out, or copy it to the clipboard. Or, you can use the output of the query as the record source for a form or report.

An action query, as the name implies, performs a task with the data. Action queries can be used to create new tables, add data to existing tables, update data, or delete data.

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Macros

Macros in Access can be thought of as a simplified programming language which you can use to add functionality to your database. For example, you can attach a macro to a command button on a form so that the macro runs whenever the button is clicked. Macros contain actions that perform tasks, such as opening a report, running a query, or closing the database. Most database operations that you do manually can be automated by using macros, so they can be great timesaving devices.

Modules

Modules, like macros, are objects you can use to add functionality to your database. Whereas you create macros in Access by choosing from a list of macro actions, you write modules in the Visual Basic for Applications (VBA) programming language. A module is a collection of declarations, statements, and procedures that are stored together as a unit. A module can be either a class module or a standard module. Class modules are attached to forms or reports, and usually contain procedures that are specific to the form or report they're attached to. Standard modules contain general procedures that aren't associated with any other object. Standard modules are listed under Modules in the Navigation Pane, whereas class modules are not.

Note:

Some Access databases contain links to tables that are stored in other databases. For example, you may have one Access database that contains nothing but tables, and another Access database that contains links to those tables, as well as queries, forms, and reports that are based on the linked tables. In most cases, it does not matter whether a table is a linked table or actually stored in the database.

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Check your progress – 2

Fill in the blanks

a) ………………… is an object-oriented relational database management system.

b) ……………….. are what you use to format, summarize and present data.

c) Retrieve data by using a ……………..

d) ……………. Are used to store data.

5.4 RELATIONAL DATA BASE MANAGEMENT SYSTEM

Learning Objective :-

After studying this sub unit you would be able to – i. Define relational database management system ii. Explain its advantages and disadvantages

A relational

database management

system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd , of IBM's San

Jose Research Laboratory . Many popular databases currently in use are based on the relational database model.

Relational databases have often replaced legacy hierarchical databases and network databases because they are easier to understand and use. However, relational databases have been challenged by object databases , which were introduced in an attempt to address the objectrelational impedance mismatch in relational database, and XML databases .

Relational database management system is a type of database management system

(DBMS) that stores data in the form of related tables . Relational databases are powerful because they require few assumptions about how data is related or how it will be extracted from the database. As a result, the same database can be viewed in many different ways.

An important feature of relational systems is that a single database can be spread across several tables. This differs from flat-file databases , in which each database is self-contained in a single table.

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What is table?

The data in RDBMS is stored in database objects called tables. The table is a collection of related data entries and it consists of columns and rows.

Remember, a table is the most common and simplest form of data storage in a relational database. Following is the example of a CUSTOMERS table:

ID

1

2

3

4

5

6

NAME

Ramesh

Khilan kaushik

Chaitali

Hardik

Komal

AGE

32

25

23

25

27

22

ADDRESS

Ahmedabad

Delhi

Kota

Mumbai

Bhopal

MP

SALARY

2000.00

1500.00

2000.00

6500.00

8500.00

4500.00

What is field?

Every table is broken up into smaller entities called fields. The fields in the CUSTOMERS table consist of ID, NAME, AGE, ADDRESS and SALARY.

A field is a column in a table that is designed to maintain specific information about every record in the table.

What is record or row?

A record, also called a row of data, is each individual entry that exists in a table. For example there are 7 records in the above CUSTOMERS table. Following is a single row of data or record in the CUSTOMERS table:

Ahmedabad 2000.00 1 Ramesh

A record is a horizontal entity in a table.

32

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What is column?

A column is a vertical entity in a table that contains all information associated with a specific field in a table.

For example, a column in the CUSTOMERS table is ADDRESS, which represents location description and would consist of the following:

What is NULL value?

A NULL value in a table is a value in a field that appears to be blank, which means a field with a

NULL value is a field with no value.

It is very important to understand that a NULL value is different than a zero value or a field that contains spaces. A field with a NULL value is one that has been left blank during record creation.

SQL Constraints:

Constraints are the rules enforced on data columns on table. These are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the database.

Constraints could be column level or table level. Column level constraints are applied only to one column where as table level constraints are applied to the whole table.

Following are commonly used constraints available in SQL:

Not null constraint : ensures that a column cannot have null value.

Default constraint

Unique constraint

Primary key

Foreign key

: provides a default value for a column when none is specified.

: ensures that all values in a column are different.

: uniquely identified each rows/records in a database table.

: uniquely identified a rows/records in any another database table.

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Check Constraint : The CHECK constraint ensures that all values in a column satisfy certain conditions.

Index : Use to create and retrieve data from the database very quickly.

Data Integrity:

The following categories of the data integrity exist with each RDBMS:

Entity Integrity: There are no duplicate rows in a table.

Domain Integrity: Enforces valid entries for a given column by restricting the type, the format, or the range of values.

Referential integrity: Rows cannot be deleted, which are used by other records.

User-Defined Integrity: Enforces some specific business rules that do not fall into entity, domain or referential integrity.

Database Normalization

Database normalization is the process of efficiently organizing data in a database. There are two reasons of the normalization process:

Eliminating redundant data, for example, storing the same data in more than one tables.

Ensuring data dependencies make sense.

Both of these are worthy goals as they reduce the amount of space a database consumes and ensure that data is logically stored. Normalization consists of a series of guidelines that help guide you in creating a good database structure.

Normalization guidelines are divided into normal forms; think of form as the format or the way a database structure is laid out. The aim of normal forms is to organize the database structure so that it complies with the rules of first normal form, then second normal form, and finally third normal form.

Popular Relational Databases

In this article, we are going to introduce three major and important open-source relational database management systems that have helped to shape the world of application development.

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SQLite: A very powerful, embedded relational database management system.

MySQL: The most popular and commonly used RDBMS.

PostgreSQL: The most advanced, SQL-compliant and open-source objective-RDBMS.

SQLite:

SQLite is an amazing library that gets embedded inside the application that makes use of. As a self-contained, file-based database, SQLite offers an amazing set of tools to handle all sorts of data with much less constraint and ease compared to hosted, process based (server) relational databases.

When an application uses SQLite, the integration works with functional and direct calls made to a file holding the data (i.e. SQLite database) instead of communicating through an interface of sorts (i.e. ports, sockets). This makes SQLite extremely fast and efficient and also powerful thanks to the library are underlying technology.

Advantages of SQLite:

File based: The entire database consists of a single file on the disk, which makes it extremely portable.

Standards-aware: Although it might appear like a "simple" DB implementation, SQLite

 uses SQL. It has some features omitted (RIGHT OUTER JOIN or FOR EACH

STATEMENT), however, some additional ones are baked in.

Great for developing and even testing: During the development phase of most applications, for a majority of people it is extremely likely to need a solution that can scale for concurrency. SQLite, with its rich feature base, can offer more than what is needed for development with the simplicity of working with a single file and a linked C based library.

Disadvantages of SQLite

No user management: Advanced databases come with the support for users, i.e. managed connections with set access privileges to the database and tables. Given the

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purpose and nature of SQLite (no higher-levels of multi-client concurrency), this feature does not exist.

Lack of possibility to tinker with for additional performance: Again by design,

SQLite is not possible to tinker with to obtain a great deal of additional performance. The library is simple to tune and simple to use. Since it is not complicated, it is technically not possible to make it more performing than it already, amazingly is.

When To Use SQLite

Embedded applications: All applications that need portability, that do not require

 expansion, e.g. single-user local applications, mobile applications or games.

Disk access replacement: In many cases, applications that need to read/write files to disk directly can benefit from switching to SQLite for additional functionality and simplicity that comes from using the Structured Query Language (SQL).

Testing: It is an over kill for a large portion of applications to use an additional process for testing the business-logic (i.e. the application's main purpose: functionality).

When Not To Use SQLite

Multi-user applications: If you are working on an application whereby multiple clients need to access and use the same database, a fully-featured RDBM (e.g. MySQL) is probably better to choose over SQLite.

Applications requiring high write volumes: One of the limitations of SQLite is the write operations. This DBMS allows only one single write*operating to take place at any given time, hence allowing a limited throughput.

MySQL

MySQL is the most popular one of all the large-scale database servers. It is a feature rich, opensource product that powers a lot of web-sites and applications online. Getting started with

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MySQL is relatively easy and developers have access to a massive array of information regarding the database on the internet.

Advantages of MySQL

Easy to work with: MySQL can be installed very easily. Third-party tools, including

 visual ones (i.e. GUIs) make it extremely simple to get started with the database.

Feature rich: MySQL supports a lot of the SQL functionality that is expected from a

RDBMS -- either directly or indirectly.

Secure: A lot of security features, some rather advanced, are built in MySQL.

Scalable and powerful: MySQL can handle a lot of data and furthermore it can be used

"at scale", if needed be.

Speedy: Giving up some standards allows MySQL to work very efficiently and cut corners, thus providing speed gains.

Disadvantages of MySQL

Known limitations: By design, MySQL does not intend to do everything and it comes with functional limitations that some state-of-the-art applications might require .

Reliability issues: The way certain functionality gets handled with MySQL (e.g. references, transactions, auditing etc.) renders it a little-less reliable compared to some other RDBMSs.

Stagnated development: Although MySQL is still technical an open-source product, there are complaints regarding the development process since its acquisition. However, it should be noted that there are some MySQL-based, fully-integrated databases that add value on top of the standard MySQL installations (e.g. MariaDB).

When to Use MySQL

Distributed operations: When you need more than what SQLite can offer, including

MySQL to your deployment stack, just like any stand-alone database server, brings a lot of operational freedom together with some advanced features.

High security: MySQL's security features provide reliable protection for data-access

(and use) in a simple way.

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Web-sites and web-applications: A great majority of web-sites (and web-applications) can simply work on MySQL despite the constraints. This flexible and somewhat scalable tool is easy to use and easy to manage -- which proves very helpful in the long run.

Custom solutions: If you are working on a highly specific and extremely custom solution, MySQL can tag along easily and go by your rules thanks to its rich configuration settings and operation modes.

When Not To Use MySQL

SQL compliance: Since MySQL does not [try to] implement the full SQL standard, this tool is not completely SQL compliant. If you might need integration with such RDBMSs, switching from MySQL will not be easy.

Concurrency: Even though MySQL and some storage engines perform really well with read operations, concurrent read-writes can be problematic.

Lack of features: Again, depending on the choice of the database-engine, MySQL can lack certain features, such as the full-text search.

PostgreSQL:

PostgreSQL is the advanced, open-source [object]-relational database management system which has the main goal of being standards-compliant and extensible. PostgreSQL, or Postgres, tries to adopt the ANSI/ISO SQL standards together with the revisions.

Compared to other RDBMSs, PostgreSQL differs itself with its support for highly required and integral object-oriented and/or relational database functionality, such as the complete support for reliable transactions, i.e. Atomicity, Consistency, Isolation, Durability (ACID).

Due to the powerful underlying technology, Postgres is extremely capable of handling many tasks very efficiently. Support for concurrency is achieved without read locks thanks to the implementation of Multiversion Concurrency Control (MVCC), which also ensures the ACID compliance.

PostgreSQL is highly programmable, and therefore extendible, with custom procedures that are called "stored procedures". These functions can be created to simplify the execution of repeated, complex and often required database operations.

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Although this DBMS does not have the popularity of MySQL, there are many amazing thirdparty tools and libraries that are designed to make working with PostgreSQL simple, despite this database's powerful nature. Nowadays it is possible to get PostgreSQL as an application package through many operating systems default package manager with ease .

Advantages of PostgreSQL

An open-source SQL standard compliant RDBMS: PostgreSQL is open-source and

 free, yet a very powerful relational database management system.

Strong community: PostgreSQL is supported by a devoted and experienced community

 which can be accessed through knowledge-bases and Q&A sites 24/7 for free.

Strong third-party support: Regardless of the extremely advanced features,

PostgreSQL is adorned with many great and open-source third-party tools for designing, managing and using the management system.

Extensible: It is possible to extend PostgreSQL programmatically with stored

 procedures, like an advanced RDBMS should be.

Objective: PostgreSQL is not just a relational database management system but an objective one - with support for nesting, and more.

Disadvantages of PostgreSQL

Performance: For simple read-heavy operations, PostgreSQL can be an over-kill and

 might appear less performing than the counterparts, such as MySQL.

Popularity: Given the nature of this tool, it lacks behind in terms of popularity, despite the very large amount of deployments - which might affect how easy it might be possible to get support.

Hosting: Due to above mentioned factors, it is harder to come by hosts or service providers that offer managed PostgreSQL instances.

When To Use PostgreSQL

Data integrity: When reliability and data integrity are an absolute necessity without

 excuses, PostgreSQL is the better choice.

Complex, custom procedures: If you require your database to perform custom procedures, PostgreSQL, being extensible, is the better choice.

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Integration: In the future, if there is a chance of necessity arising for migrating the entire database system to a propriety (e.g. Oracle) solution, PostgreSQL will be the most compliant and easy to handle base for the switch.

Complex designs: Compared to other open-source and free RDBMS implementations, for complex database designs, PostgreSQL offers the most in terms of functionality and possibilities without giving up on other valuable assets.

When Not To Use PostgreSQL

Speed: If all you require is fast read operations, PostgreSQL is not the tool to go for.

Simple set ups: Unless you require absolute data integrity, ACID compliance or complex designs, PostgreSQL can be an over-kill for simple set-ups.

Replication: Unless you are willing to spend the time, energy and resources, achieving replication with MySQL might be simpler for those who lack the database and system administration experience.

5.4.1 ADVANTAGE

Data Structure: The table format is simple and easy for database users to understand and use.

RDBMSs provide data access using a natural structure and organization of the data. Database queries can search any column for matching entries.

Multi-User Access: RDBMSs allow multiple database users to access a database simultaneously. Built-in locking and transactions management functionality allow users to access data as it is being changed, prevents collisions between two users updating the data, and keeps users from accessing partially updated records.

Privileges: Authorization and privilege control features in an RDBMS allow the database administrator to restrict access to authorized users, and grant privileges to individual users based on the types of database tasks they need to perform. Authorization can be defined based on the

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remote client IP address in combination with user authorization, restricting access to specific external computer systems.

Network Access: RDBMSs provide access to the database through a server daemon, a specialized software program that listens for requests on a network, and allows database clients to connect to and use the database. Users do not need to be able to log in to the physical computer system to use the database, providing convenience for the users and a layer of security for the database. Network access allows developers to build desktop tools and Web applications to interact with databases.

Speed: The relational database model is not the fastest data structure. RDBMS advantages, such as simplicity, make the slower speed a fair trade-off. Optimizations built into an RDBMS, and the design of the databases, enhance performance, allowing RDBMSs to perform more than fast enough for most applications and data sets. Improvements in technology, increasing processor speeds and decreasing memory and storage costs allow systems administrators to build incredibly fast systems that can overcome any database performance shortcomings.

Maintenance: RDBMSs feature maintenance utilities that provide database administrators with tools to easily maintain, test, repair and back up the databases housed in the system. Many of the functions can be automated using built-in automation in the RDBMS, or automation tools available on the operating system.

Language: RDBMSs support a generic language called "Structured Query Language" (SQL).

The SQL syntax is simple, and the language uses standard English language keywords and phrasing, making it fairly intuitive and easy to learn. Many RDBMSs add non-SQL, databasespecific keywords, functions and features to the SQL language.

5.4.2 DISADVANTAGES

Cost: One disadvantage of relational databases is the expensive of setting up and maintaining the database system. In order to set up a relational database, you generally need to purchase special software.

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Abundance of Information: Advances in the complexity of information cause another drawback to relational databases. Relational databases are made for organizing data by common characteristics. Complex images, numbers, designs and multimedia products defy easy categorization leading the way for a new type of database called object-relational database management systems. These systems are designed to handle the more complex applications and have the ability to be scalable.

Stuctured Limits: Some relational databases have limits on field lengths. When you design the database, you have to specify the amount of data you can fit into a field. Some names or search queries are shorter than the actual, and this can lead to data loss.

Isolated Databases: Complex relational database systems can lead to these databases becoming

"islands of information" where the information cannot be shared easily from one large system to another. Often, with big firms or institutions, you find relational databases grew in separate divisions differently. For example, maybe the hospital billing department used one database while the hospital personnel department used a different database. Getting those databases to

"talk" to each other can be a large, and expensive, undertaking, yet in a complex hospital system, all the databases need to be involved for good patient and employee care.

Check your progress – 3

Fill in the blanks

a) ……………………………… is a type of database management system

(DBMS) that stores data in the form of related tables .

b) …………………… means there are no duplicate rows in a table.

c) ……………… is a very powerful, embedded relational database management system.

d) …………………The most advanced, SQL-compliant and open-source objective-

RDBMS

e) ………………………… is the process of efficiently organizing data in a database.

5.5 DEVISING TABLES AND RELATIONSHIPS

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Learning Objective :-

After studying this sub unit you would be able to – i. Define table ii. Explain table and relationship

Introduction to tables

When you use a database, you store your data in tables — subject-based lists that contain data arranged in records. For instance, you might create a Contacts table to store a list of names, email addresses, and telephone numbers.

A table is a database object that you use to store data about a particular subject, such as employees or products. A table consists of records and fields.

Each record contains data about one instance of the table subject, such as a particular employee.

A record is also commonly called a row or an instance.

Each field contains data about one aspect of the table subject, such as first name or e-mail address. A field is also commonly called a column or an attribute.

A record consists of field values, such as Contoso, Ltd. or [email protected] A field value is also commonly called a fact.

1. A record

2. A field

3. A field value

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A database can contain many tables, each storing information about a different subject. Each table can contain many fields of different types of data, such as text, numbers, dates, and hyperlinks.

External Data

You can link to a variety of external data sources, such as other databases, text files, and Excel workbooks. When you link to external data, Access can use the link as if it were a table.

Depending on the external data source and the way that you create the link, you can edit the data in the linked table, and can create relationships that involve the linked table. However, you cannot change the design of the external data by using the link.

Table and Field Properties

Tables and fields have properties that you can set to control their characteristics or behavior.

A table open in Design view.

1. Table properties

2. Field properties

Table Properties:

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In an Access database, table properties are attributes of a table that affect the appearance or behavior of the table as a whole. Table properties are set in the table's property sheet, in Design view. For example, you can set a table's Default View property to specify how the table is displayed by default.

Field Properties:

A field property applies to a particular field in a table and defines one of the field's characteristics or an aspect of the field's behavior. You can set some field properties in Datasheet view. You can also set any field property in Design view by using the Field Properties pane.

Data Types

Every field has a data type. A field's data type indicates the kind of data that the field stores, such as large amounts of text or attached files.

A data type is a field property, but it differs from other field properties as follows:

You set a field's data type in the table design grid, not in the Field

Properties pane.

A field's data type determines what other properties the field has.

You must set a field's data type when you create the field.

TABLE RELATIONSHIPS

To store your data, you create one table for each type of information that you track. Types of information might include customer information, products, and order details. To bring the data from multiple tables together in a query, form, or report, you define relationships between the tables.

Note:

In a web database, you cannot use the Relationships object tab to create relationships. You can use lookup fields to create relationships in a web database.

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Note:

1. Customer information that once existed in a mailing list now resides in the Customers table.

2. Order information that once existed in a spreadsheet now resides in the Orders table.

3. A unique ID, such as a Customer ID, distinguishes one record from another within a table. By adding one table's unique ID field to another table and defining a relationship between the two fields, Access can match related records from both tables so that you can bring them together in a form, report, or query.

Although each table stores data about a different subject, tables in a database usually store data about subjects that are related to each other. For example, a database might contain:

A customers table that lists your company‘s customers and their addresses.

A products table that lists the products that you sell, including prices and pictures for each item.

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An orders table that tracks customer orders.

Because you store data about different subjects in separate tables, you need some way to tie the data together so that you can easily combine related data from those separate tables. To connect the data stored in different tables, you create relationships. A relationship is a logical connection between two tables that specifies fields that the tables have in common.

Keys

Fields that are part of a table relationship are called keys. A key usually consists of one field, but may consist of more than one field. There are two kinds of keys:

Primary key A table can have only one primary key. A primary key consists of one or more fields that uniquely identify each record that you store in the table. Often, there is a unique identification number, such as an ID number, a serial number, or a code, that serves as a primary key. For example, you might have a Customers table where each customer has a unique customer ID number. The customer ID field is the primary key of the Customers table. When a primary key contains more than one field, it is usually composed of pre-existing fields that, taken together, provide unique values. For example, you might use a combination of last name, first name, and birth date as the primary key for a table about people.

Foreign key A table can also have one or more foreign keys. A foreign key contains values that correspond to values in the primary key of another table. For example, you might have an Orders table in which each order has a customer ID number that corresponds to a record in a Customers table. The customer ID field is a foreign key of the Orders table.

The correspondence of values between key fields forms the basis of a table relationship. You use a table relationship to combine data from related tables. For example, suppose that you have a

Customers table and an Orders table. In your Customers table, each record is identified by the primary key field, ID.

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To associate each order with a customer, you add a foreign key field to the Orders table that corresponds to the ID field of the Customers table, and then create a relationship between the two keys. When you add a record to the Orders table, you use a value for customer ID that comes from the Customers table. Whenever you want to view any information about an order's customer, you use the relationship to identify which data from the Customers table corresponds to which records in the Orders table.

A table relationship, shown in the Relationships window:

1. A primary key, identified by the key icon next to the field name.

2. A foreign key — note the absence of the key icon.

Table Specifications

In Access 2010, a table has the following practical limits:

ATTRIBUTE

Number of characters in a table name

Number of characters in a field name

Number of fields in a table

MAXIMUM

64

64

255

167

Number of open tables

Table size

Number of characters in a Text field

Number of characters in a Memo field

2048; this limit includes tables opened internally by Access

2 gigabytes, minus the space needed for the system objects

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65,535 when entering data through the user interface;

2 gigabytes of character storage when entering data programmatically

Size of an OLE Object field

Number of indexes in a table

Number of fields in an index

1 gigabyte

32

10

Number of characters in a validation message

Number of characters in a validation rule

255

2,048

Number of characters in a table or field description 255

Number of characters in a record (excluding Memo 4,000 and OLE Object fields) when the Unicode

Compression property of the fields is set to Yes

Number of characters in a field property setting 255

Benefits of Using Relationships:

Keeping data separated in related tables produces the following benefits:

Consistency Because each item of data is recorded only once, in one table, there is less opportunity for ambiguity or inconsistency. For example, you store a customer's name only once, in a table about customers, rather than storing it repeatedly (and potentially inconsistently) in a table that contains order data.

Efficiency Recording data in only one place means you use less disk space. Moreover, smaller tables tend to provide data more quickly than larger tables. Finally, if you don't use separate tables for separate subjects, you will introduce null values (the absence of data) and redundancy into your tables, both of which can waste space and impede performance.

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Comprehensibility The design of a database is easier to understand if the subjects are properly separated into tables.

Check your progress – 4

Fill in the blanks

a) A table consists of …………. and ……………….

b) A …………… property applies to a particular field in a table defines one of the field's characteristics.

c) A ………………… determines what other properties the field has.

d) Fields that are part of a table relationship are called ………………………...

e) A table can have only ……………….. primary key

f) A ……………… note the absence of the key icon

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Let Us Sum Up (Summary):

a) A database is a tool for collecting and organizing information.

b) A database management system (DBMS) is a collection of programs that enables you to store, modify, and extract information from a database.

c) Access is an object-oriented relational database management system.

d) A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd , of

IBM's San Jose Research Laboratory .

e)

Database normalization is the process of efficiently organizing data in a database.

f) A table is a database object that you use to store data about a particular subject, such as employees or products.

g) Table properties are attributes of a table that affect the appearance or behavior of the table as a whole.

h) A field property applies to a particular field in a table and defines one of the field's characteristics or an aspect of the field's behavior.

i) A relationship is a logical connection between two tables that specifies fields that the tables have in common.

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Answers:

Check Your Progress – 1

a) Database

b) Objects

c) Database management system

d) SQL

e) Fourth generation languages

Check Your Progress – 2

a) Access

b) Reports

c) Query

d) Tables

Check Your Progress – 3

a) Relational database management system

b) Entity integrity

c) SQLite

d) PostgreSQL

e) Data Normalization

Check Your Progress – 4

a) Records , fields

b) Field

c) Fields data type

d) Key

e) One

f) Foreign key

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BHOJ (OPEN) UNIVERSITY

Self learning material

Of

Course – 7, Unit – 6

Internet

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UNIT – 6 INTERNET

6.1 Introduction to Internet

6.1.1 Net Browsing

6.1.2 Types of Browsers

6.1.3 Email - Outlook Express

6.1.4 Web Enabled

6.1.5 Components and Software Required To Run Multimedia Website

6.1.6 Saving and Printing Web Files

6.2 Networking

6.2.1 Types

6.2.2 Topology

6.3 Computer Crime and Security

6.3 Application in Development Sector

Let Us Sum Up (Summary)

Answers

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6.1 INTRODUCTION TO INTERNET

Learning Objective :-

After studying this sub unit you would be able to – x. Define internet xi. Explain net browsers and types of browsers xii. Explain Email - outlook express and web enabled xiii. Describe the components and software required to run multimedia website xiv. Understand how to print and save web files

The internet has come a long way since the 1960s. The internet today is not a hierarchical structure. It is made up of many wide and local area networks joined by connecting devices and switching stations. It is difficult to give an accurate representation of the internet because it is continually changing.

What is Internet?

A network is a group of connected communicating devices such as computers and printers. An internet is two or more networks that can communicate with each other. Internet is a collaboration of more than hundreds of thousands of interconnected networks. Private individuals as well as various organizations such as government agencies, school, research facilities, corporations, and libraries in more than 100 countries use the internet. Millions of people are users. Yet this extraordinary communication system only came into being in 1969.

The Internet is a worldwide network of computer networks that connects university, government, commercial, and other computers in the world. Using the Internet, you can send electronic mail, chat with colleagues around the world, and obtain information on a wide variety of subjects.

The Internet is a collection of networks connected by interconnecting devices.

A means of connecting a computer to any other computer anywhere in the world via dedicated routers and servers . Internet can be defined as the wired or wireless mode of communication through which one can receive, transmit information that can be used for single or multiple operations.

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History of Internet ?

In the mid 1960s, mainframe computers in research organizations were stand alone devices. The

Advance Research Project Agency (ARPA) in the Department of Defense (DOD) was interested in finding a way to connect computers.

In 1967, at an Association for Computing Machinery (ACM) meeting, ARPA presented its ideas for ARPANET, a small network of connected computers. The idea was that each host computer would be attached to a specialized computer, called an interface message processor (IMP).

By 1969, Arpanet was a reality. Four nodes, at the University of California at Los Angeles

(UCLA), the University of California at Santa Barbara (UCSB), Stanford research institute

(SRI), and the University of Utah, were connected via the IMPs to form a network.

In 1972, Vint Cerf and Bob Kahn, both of whom were part of the core ARPANET group, collaborated on what they called the Internetting project. Cerf and Kahn in 1973 outlined the protocols to achieve end-to-end delivery of packets. This is the transmission control protocol

(TCP). Shortly TCP split into two protocols: Transmission Control Protocol (TCP) and

Internetworking Protocol (IP).

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6.1.1 NET BROWSING

The words ―Browsing‖ or ―Surfing‖ are used to describe the process of looking at documents, websites and web pages on the Internet. Browsing behaviour differs from person to person. To access a website you can either type the domain name (the website address – more later) of the website directly into the address bar or you can use a search engine to search for the site using the business name or some other keywords that you know can be found on the website.

The word browsing is used to refer to a reading process which is done randomly through unhurried and casual inspection.

"Browsing is a quick examination of the relevance of a number of objects

which may or may not lead to a closer examination or

acquisition/selection of (some of) these objects.

-

Hjørland

Browsing is often understood as a random activity. Dictionary.com, for example, has this definition: "to glance at random through a book, magazine, etc."

Categories of browsing –

Bawden (1986) identifies three categories of browsing activity:

Purposive browsing, which is the purposeful search for new information in a defined, broad subject area

Capricious browsing, which describes the random search of material without a clearly defined goal, and

Exploratory or semi-purposive browsing ―in search, quite literally of inspiration‖.

Cove and Walsh (1988) also divide browsing, into three categories of online activity:

Search browsing, which is directed and structured, and where the end destination is known

General purpose browsing, which involves regularly consulting websites that are expected to contain items of interest, and

Serendipity browsing, which is wholly random, unstructured and undirected.

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6.1.2 TYPES OF BROWSERS

A browser is a software application used to locate, retrieve and display content on the World

Wide Web , including Web pages , images, video and other files. As a client/server model , the browser is the client run on a computer that contacts the Web server and requests information.

The Web server sends the information back to the Web browser which displays the results on the computer or other Internet-enabled device that supports a browser.

A browser is software that is used to access the internet. A browser lets you visit websites and do activities within them like login, view multimedia, link from one site to another, visit one page from another, print, send and receive email, among many other activities.

Although the primary application of all the web browsers is the same, they differ from each other in more than one aspect. The distinguishing areas are:

Platform: Linux, Windows, Mac, BSD and other Unix

Protocols: FTP, SFTP, SAMBA, HTTP, IMAP, etc.

Graphical User Interface (GUI)

Layout Engine: Amaya, Gecko, Trident, KHTML, WebKit

Mobile Compatibility

HTML5 Support

Open Source

Proprietary

However, the general, primary and secondary features and facilities offered by web browsers include download, bookmarks, and password management. They also offer functions like spell checking, search engine toolbars, tabbed browsing, advertisement filtering, HTML access keys and pop-up blocking.

The most popular browsers are Microsoft Internet Explorer , Firefox , Google Chrome , Apple

Safari and Opera . While most commonly use to access information on the web, a browser can also be used to access information hosted on Web servers in private networks .

The different types of browsers are:-

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Internet Explorer

Internet Explorer (IE) is a product from software giant Microsoft. This is the most commonly used browser in the universe. This was introduced in 1995 along with Windows 95 launch and it has passed Netscape popularity in 1998.

Features:

There are regular Microsoft updates that IE supports. Favicon allows an image to be used as a bookmark. It supports Integrated Windows Authentication.

Netscape

Netscape is one of the original Web browsers. This is what Microsoft designed Internet Explorer to compete against. Netscape and IE comprise the major portion of the browser market. Netscape was introduced in 1994.

Features:

Netscape Messenger is an email and news client for Netscape Navigator 9. Also, another feature is Netscape Publishing System that allows commercial sites to publish articles and charge users for accessing them.

Mozilla

Mozilla is an open-source Web browser, designed for standards compliance, performance and portability. The development and testing of the browser is coordinated by providing discussion forums, software engineering tools, releases and bug tracking. Browsers based on Mozilla code is the second largest browser family on the Internet today, representing about 30% of the Internet community.

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Chrome

This web browser was developed by Google. Its beta and commercial versions were released in

September 2008 for Microsoft Windows. The browser options are very similar to that of Safari, the settings locations are similar to Internet Explorer 7, and the window design is based on

Windows Vista.

Features:

The main standout feature is the malware and phishing warning that the browser suggests when the user wants to browse a site. Also, there is a user tracking option available with Chrome.

Konqueror it is a KHTML based engine that was developed by KDE and initially released in 1996. It supports protocols like FTP, SFTP, SAMBA, HTTP, IMAP and others.

Features:

Konqueror is an Open Source web browser with HTML 4.01 compliance, supporting Java applets, JavaScript, CSS 1, CSS 2.1, as well as Netscape plugins. This works as a file manager as well as supports basic file management on local UNIX file systems, from simple cut/copy and paste operations to advanced remote and local network file browsing

Firefox

Firefox is a new browser derived from Mozilla. It was released in 2004 and has grown to be the second most popular browser on the Internet.

Features:

As it is an open source software, it allows everyone to access the code. It supports tabbed browsing that allows the user to open multiple sites in a single window. Session storage is also

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an important feature of Firefox, which allows the user to regain access to the open tabs after he has closed the browser window.

Safari

Safari is a web browser developed by Apple Inc. and included in Mac OS X. It was first released as a public beta in January 2003.

Features:

Safari has very good support for latest technologies like XHTML, CSS2 etc.

Safari is based on open source software and is one of the fastest browsers available. The Safari 4 beta had many features like Voice Over screen reader, that reads aloud everything that is on the screen, including text and web links. Also, there is a resizable web search box option available.

'Grammar Checking' is an interesting built-in feature.

Opera

This browser was developed by Opera Software in 1996. It is a well-known browser that is mainly used in Internet-activated mobile phones, PDAs, and smartphones. Opera Mini and Opera

Mobile are the browsers used in smartphones. It is compatible with many operating systems such as Solaris, Linux, Mac OS X, and Microsoft Windows.

Features:

Opera is smaller and faster than most other browsers, yet it is full- featured. Fast, user-friendly, with keyboard interface, multiple windows, zoom functions, and more. Java and non Javaenabled versions available.

Lynx

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Lynx is a fully-featured World Wide Web browser for users on Unix, VMS, and other platforms running cursor-addressable, character-cell terminals or emulators.

Features:

Though being the oldest amongst the current lot of web browsers, it can be remotely accessed over Telnet and SSH. This feature enables Lynx to be used for testing a website's performance from any geographical location.

6.1.3 E-MAIL - OUTLOOK EXPRESS

One of the most popular internet services is electronic mail (e – mail). The designers of the internet probably never imagined the popularity of this application program.

At the beginning of the internet era, the messages sent by electronic mail were short and consisted of text only, they let people exchange quick memos. Today electronic mail is much more complex. It allows a message to include text, audio, and video. It also one message to be sent to one or more recipients.

The first e-mail was sent by Ray Tomlinson in 1971 . By 1996 , more electronic mail was being sent than postal mail.

Features of using email

It's quick – recipient receives your email as soon as they go online and collect their mail.

It's secure.

It's low cost.

Photos, documents and other files can be attached to an email, so that more information can be shared.

One email can be sent to more than one recipient at a time.

Email address

Like your address on envelopes, your email address tells people who you are and where you live, and it is unique — one of a kind. Nobody else in the world has the same email address as you.

Your email address is usually made up like this: your user name for connecting to the

Internet (AT) the name of your Internet Service Provider (DOT) based at this kind of organization (DOT) in this country

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How to send and receive e-mail

To send and receive e-mail messages you can use an e-mail program, also known as an e-mail

client such as Microsoft Outlook or Mozilla Thunderbird . When using an e-mail client you must have a server that stores and delivers your e-mail this service is provided by your ISP but can also be a service provided by another company. The e-mail client will connect to the server to download all new e-mail and deliver any unsent e-mail.

An alternative way of sending and receiving e-mail and a more popular solution for most people is an online e-mail service or webmail such as Hotmail , Gmail , and Yahoo Mail . Many of the online e-mail services including the above examples are free or have a free account option.

OUTLOOK EXPRESS

To access an e-mail account you also need an e-mail program, which is also called e-mail client software. You use e-mail program to open, print, delete, reply to, forward and save mail from your email server. One such program is Microsoft outlook express, which install as part of internet explorer.

Outlook Express is an email program that works with Internet Explore versions 4.0 to 6.0. This product is typically bundled with Microsoft Windows (Windows 98 to Windows XP). However, the product isn‘t available with Windows Vista, which was replaced with ―Windows Mail.‖

Outlook Express is designed for use with any Internet standard system, for example, Simple Mail

Transfer Protocol (SMTP), Post Office Protocol 3 (POP3), and Internet Mail Access Protocol

(IMAP).

Working of Outlook Express

To put in simpler terms, you just need to set-up an Outlook Express profile with the help of the login details that you use to log in to any email service provider. Once done, the outlook Express,

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then retrieves your email by connecting to the web mail service you use and downloads all the messages from the web mail service in your computer, deleting them simultaneously from the web mail service .

Features Outlook Express

Microsoft Outlook Express puts the world of online communication on your desktop. Whether you want to exchange e-mail with colleagues and friends or join newsgroups to trade ideas and information, the tools you need are here.

Manage multiple e-mail and newsgroup accounts

Browse through messages quickly and easily

Keep your e-mail on a server so you can view it from more than one computer

Use the Address Book to store and retrieve e-mail address

Add a personal signature or stationary to you messages

Send and receive secure messages

Find newsgroups that interest you

View newsgroup conversations efficiently

Download newsgroup messages for offline reading

Improved Security

In the past, Outlook Express was targeted for malicious viruses. The script could be opened as an attachment which made it easier for people to infect others with viruses. Also, previewing email could allow a virus to run without the user‘s knowledge. Microsoft has worked hard to correct these security holes.

New versions of Outlook Express block outside images, which prevents virus infection. It also disables scripts and has strict restrictions for content transfer. The program now warns users when they‘re about to open a malicious email. If you get this message, make sure to delete the email immediately.

Configuration Outlook Express

Before you can use Outlook Express to send and receive e-mail, you need to set up an account.

You can have more than one account—for business, online shopping, and so on—and each

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person who uses your computer may have their own, completely separate account. Outlook

Express gracefully handles it all.

Launch Outlook Express

Email message storage and management in Outlook Express

In Outlook Express, all incoming emails arrive at the INBOX folder. The three other default folders are Sent items, Drafts and the Outbox. Any email you send from Outlook Express is automatically moved to the Sent Items folder. The program lets you create additional folders under the Inbox and segregate your messages as you like. This is a big help in organizing your emails. For example, you can create separate folders called "Office", "Friends", or "Family" and place the respective email messages in them. The program also provides an automated method called Outlook Express Message Rules with which you can create rules and have them applied to all incoming emails. Thus, for instance, you can have certain messages moved to designated folders, replied to automatically or even delete without your involvement.

To send an e-mail message:

Press the new mail button on the outlook express toolbar

Type the e-mail address of the recipient

Type your subject matter

Type your message and then click the send button

To retrieve mail that has been send to you:

Click on the Send/Recv button on the toolbar

Outlook express will contact your e-mail server and download your e-mail message

To reply to a message:

Click the reply button

The recipient address and the subject matter are automatically filled in

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When you have completed typing, click on the send button

The window in the outlook express looks like:

Advantages of using Outlook Express

With the help of Outlook Express, you can download, read and reply to your mails offline.

From a single account, you can access and read all the mails and can even zero down the account through which you want to send a reply.

You can also have different users and can hence use Outlook express for a public setting such as a library or a laboratory.

6.1.4 WEB ENABLED

Web-enabled content is content that can be accessed with a web browser or via HTTP or HTTPS protocols. Computer application that is created with HTML and can therefore be accessed with a browser

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All documents on public websites and intranets are web-enabled and file shares and content management systems can be easily configured to publish (or deliver) documents in a webenabled format. This term may refer to general Web surfing, connecting to a specific Web site for some purpose or running applications within a Web browser.

The instructions, typically written in a combination of HTML and JavaScript, are embedded within the Web page that is downloaded from a Web site.

What is web-enabled software?

Like the name suggests, web-enabled software has to be ―enabled‖ to be used over the internet.

Web- enabled applications are primarily written to become desktop applications, which are only modified to be accessed over a Web browser. Most vendors just add a new layer to the existing software to enable their software to function over the internet. The system remains the same and performs the same functions as before with the only difference that the program input and output is now accessible on the web. This adaptation in most web-enabled software solutions makes it slow and complex.

Vendors who own older generation software only enable the software to be used over the web to sell their product. To avoid risks and expense associated with writing new software from scratch, vendors mostly modify their older generation applications and sell them as web-based software.

However this does not change the old engine of the software. Customers who invest in such software applications continue to get outdated technology performing the same functions as before underneath a new layer that is written so that the application works on a web browser.

When a vendor offers to web enable its software, it indicates that the application is old and the vendor is willing to only invest in modifying the same old application. Most web-enabled software applications cannot survive the test of time. In case you have already invested in webenabled software, ask your vendor the time that it would take to completely rewrite the software to make it truly web-based.

Disadvantages of Web- enabled Software:

Slow and complex

Outdated Technology

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Can‘t be integrated with other applications

6.1.5 COMPONENTS AND SOFTWARE REQUIRED TO RUN MULTIMEDIA

WEBSITE

Multimedia means that computer information can be represented through audio, video, and animation in addition to traditional media (i.e., text, graphics drawings, and images).

A good general definition is:

Multimedia is the field concerned with the computer-controlled integration of text, graphics, drawings, still and moving images (Video), animation, audio, and any other media where every type of information can be represented, stored, transmitted and processed digitally.

The basic elements of multimedia on a computer are:

Movies

Animation

Sound

Text

Still images

Special effects

Why to use Multimedia?

According to Dr. Albert Mehrabian, a specialist in interpersonal communication at the University of California says:

People recall 20% of what they see

40% of what they see & hear

70% of what they see, hear & do

Multimedia allows for seeing, hearing and doing

Multimedia Applications

Examples of Multimedia Applications include:

World Wide Web

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Multimedia Authoring, e.g. Adobe/Macromedia Director

Hypermedia courseware

Video-on-demand

Interactive TV

Computer Games

Virtual reality

Digital video editing and production systems

Multimedia Database systems

In this section, we introduce you to the inside story of multimedia i.e. about the hardware and the software which enable you to get the end product called multimedia. Understanding these concepts is very important as it is only the hardware (the computer), the software (tools for designing multimedia) which will be crucial in order to run multimedia website.

COMPONENTS REQUIRED TO RUN MULTIMEDIA WEBSITE:

The components are thus divided into five categories viz. System devices, Memory and storage devices, Input devices, Output devices, and Communication devices.

System devices –

These are the devices that are the essential components for a computer. These include microprocessor, motherboard and memory. Microprocessor is basically the heart of the computer. A microprocessor is a computer processor on a small microchip. When you turn your computer on, it is the microprocessor, which performs some operations. The microprocessor gets the first instruction from the Basic Input/output System (BIOS), which is a part of its memory.

BIOS actually load the operating system into random access memory (RAM). A motherboard is a device in the computer that contains the computer's basic circuitry and other components.

Motherboard contains computer components like microprocessor, memory, basic input/output system (BIOS), expansion slots and interconnecting circuitry.

Memory and storage devices –

A memory and storage device RAM (random access memory), also called primary memory, locates the operating system, application programs, and data in current use so that the computer's

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processor reaches them quickly. RAM is called "random access" because any storage location can be accessed randomly or directly. RAM is much faster than the hard disk; the floppy disk and the CD-ROM. RAM can be taken as short-term memory and the hard disk as the long-term memory of a computer. However, RAM might get slow when used to its limit. That is why, you need more memory to work on multimedia. Today's personal computers come with 128 or more of RAM.

A hard disk stores and provides access to large amounts of data on an electro magnetically charged surface. The disk cache holds data that has recently been read. The other type of hardware cache inside your computer is cache memory. Cache stores something temporarily e.g.

Temporary Internet files are saved in Cache.

A (CD) is a small medium that can store data pertaining to audio, video, text, and other information in digital form. Initially, CDs were read-only, but newer technology allows users to record as well. (Compact Disc, read-only memory) can store computer data in the form of text, graphics and sound.

Input devices –

A keyboard is the primary text input device of computer. The keyboard contains certain standard function keys, such as the escape key, tab, cursor movement keys and shift and control key. A mouse is also a primary input device but it is not suitable for dealing with text.

A mouse is a small device that you move across a pad in order to point to a place on a display screen and thus execute a command by clicking it. The mouse is an integral part of any personal computer.

Microphone is another input device that can interpret dictation and also enable us to input sound like the keyboard is used for text.

A digital camera records and stores photographic images in digital form that can be fed to a computer as the impressions are recorded or stored in the camera for later loading into a computer. The digital cameras are available for still as well as motion pictures.

Output devices –

A printer is a device, which on receiving the signal from computer transfers the information to paper. Earlier the printer was a popular low-cost personal computer printer; now printers have

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taken its place. Dot-matrix printer strikes the paper a line at a time while inkjet sprays ink and laser printer uses a laser beam to attract ink (also called toner).

A monitor is a device for display. It is just like a television set and is measured diagonally from two opposing corners of the picture tube. The standard monitor size is 14 inches. Very large monitors can measure 21 inches diagonal or greater.

An amplifier is an electronic device that increases the power of a signal. Amplifiers are used in audio equipments. They are also called power amplifiers. Speakers with built-in amplifiers have become an integral part of the computers today and are important for any multimedia project.

Communication devices –

Burger (1994) stated;

Effective communication is the most important criteria in Multimedia.‖

A modem modulates going out from a computer or other digital device to for a telephone line and demodulates the analog signal to convert it to a digital signal to be inputted in a computer.

Most new personal computers come with 56 Kbps modems. Modems help your computer to connect to a network

SOFTWARE REQUIRED TO RUN MULTIMEDIA WEBSITE

Multimedia content on the website requires various software

Windows Media Player

Macromedia Flash

Microsoft PowerPoint

Adobe flash player

Real Networks, Real One Player, and/or Flash Player software to be installed on your computer.

Your web browser software must support frames to view activities that contain live webcasts.

Your web browser software must be configured to accept cookies

JavaScript must be enabled in your web browser software.

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Your web browser software must be configured not to block pop-up windows

To view and print the any materials that accompany the activity, you will need software that is capable of opening a PDF file such as Adobe Acrobat

6.1.6 SAVING AND PRINTING WEB FILES

If you have accessed a long text file on the net, you may want to save it for later to read off-line

(especially if you're paying per minute for connection time!). You can also print it out later as well.

You can open files for viewing or listening without saving them first, or you may want to save files to your computer for later use. A saved file can be opened any time without a web browser or Internet connection.

The documents on the website are mostly in PDF, Word (DOC) and Excel (XLS) formats. There are also MP3 sound files, images and links to videos.

TO SAVE A WEB PAGE:

Web pages browsed on the internet can be saved on the hard disk of the computer for future

use. The process for saving web pages on the computer depends on the web browser used.

Internet Explorer users should choose 'Save As' from the File menu where 'Web Archive' should be clicked to compile the web pages, with all its contents, in a single file.

In Google Chrome from the 'Save As' option, the field 'Web Page, complete' should be selected.

Firefox users should select 'Save page As' and then 'Web page, Complete' to save the required web pages.

Internet Explorer

1. Open Internet Explorer by clicking the Start button , and then clicking Internet

Explorer.

2. Go to the webpage you want to save.

3. Click the Page button, and then click Save As.

4. Navigate to the folder where you want to save the webpage. By default, web pages are saved in the Documents folder.

5. Type a new name in the File name box if you want to change the name.

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6. In the Save as type box, do one of the following:

To save all the files associated with the page, including graphics, frames, and style sheets in their original format, select Webpage, complete.

To save all information as a single file, select Web Archive, single file (*.mht).

To save just the current HTML page, without graphics, sounds, or other files,

 select Webpage, HTML only.

To save just the text from the current webpage, select Text File.

7. Click Save.

Google Chrome

There are two ways to save a web page on Google Chrome.

Method 1:

1. Open google chrome

2. Go to the webpage you want to save.

3. Right click on the desired web page

4. Select "Save As"

5. In the "Save as type" field, drop down the list and choose "Web page, Complete"

Method 2:

1. To save a specific frame in the page

2. right-click anywhere in the frame and select "Save frame as".

Mozilla Firefox

1. Open Mozilla Firefox

2. Go to the webpage you want to save.

3. Right click on the desired web page

4. Select "Save page as" or use the following shortcut: Ctrl + S

5. In the "Save as type" field, drop down the list and choose "Web page, Complete"

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Save a document as a PDF file

You can share a document with other people by saving it in Portable Document Format (PDF).

For example, you can email the PDF file or make it available on public file servers, such as the

Public folder on your disc. Even people without the application that created the document will be able to read it as long as they have a PDF viewer, such as Preview or Adobe Acrobat.

1. Open the document you want to save as a PDF file.

2. Choose File > Print.

3. Choose ―Save as PDF‖ from the PDF pop-up menu, and then choose a name and location for the PDF file.

4. Enter the information you want in the Title, Author, Subject, and Keywords fields.

You can search on the contents of those fields using Spotlight.

5. If you want to encrypt your document, click Security Options.

You can choose two passwords: one for opening the document and another for printing or copying from the document.

TO PRINT A WEB PAGE

If you are trying to print web-pages and find that some of the content of the page is not being printed out please carry out the following operations on your internet browser

Internet explorer

1. Select the 'Tools' on the top of your internet browser.

2. Select 'Internet Options' from the drop down menu.

3. Select the 'Advanced' tab from the 'Internet Options' menu

4. Scroll down the 'Advanced' menu to the 'Printing' checkbox.

5. Click the mouse inside the 'Print background colors and images' box.

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6. Click 'Ok'

.

.

Mozilla Firefox

If your internet browser is called 'Mozilla Firefox' please follow the instructions below instead

1. Click the Firefox tab at the top left of your screen.

2. Mouse over Print… and select Page Setup

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3. Select 'Print background colors and images' in the 'Options' box.

Firefox 3x:

1. Select File > Print

2. Choose your printer, then select Properties

3. Press Page Setup

4. Click the checkbox to enable Print Background (colors and images)

Google chrome:

1. Click the Chrome controls icon at the top right of the window

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2. Select Print…

3. Click the Background colors and images box

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Check your progress – 1

a) The Internet is a collection of ………………. connected by interconnecting devices.

b) A ………………. is software that is used to access the internet.

c) The first e-mail was sent by ………………………… in 1971 .

d) All documents on public websites and intranets are …………………..

e) ………………….. allows for seeing, hearing and doing.

6.2 NETWORKING

Learning Objective :-

After studying this sub unit you would be able to – i. Define networking ii. Explain types of networking iii. Understand its topology

Networking is the practice of linking two or more computing devices together for the purpose of sharing data. Networks are built with a mix of computer hardware and computer software.

A network consists of two or more computers that are linked in order to share resources (such as printers and CDs), exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.

A computer network consists of a collection of computers, printers and other equipment that is connected together so that they can communicate with each other.

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Every network includes:

At least two computers Server or Client workstation.

Networking Interface Card's (NIC)

A connection medium, usually a wire or cable, although wireless communication between networked computers and peripherals is also possible.

Network Operating system software, such as Microsoft Windows NT or 2000, Novell

NetWare, Unix and Linux.

Network Configuration network configurati on peer- to- network client server network

Peer-to-peer networks are more commonly implemented where less than ten computers are involved and where strict security is not necessary. All computers have the same status, hence the term 'peer', and they communicate with each other on an equal footing. Files, such as word processing or spreadsheet documents, can be shared across the network and all the computers on the network can share devices, such as printers or scanners, which are connected to any one computer.

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Client/server networks are more suitable for larger networks. A central computer, or 'server', acts as the storage location for files and applications shared on the network. Usually the server is a higher than average performance computer. The server also controls the network access of the other computers which are referred to as the 'client' computers. Typically, teachers and students in a school will use the client computers for their work and only the network administrator

(usually a designated staff member) will have access rights to the server.

Advantages of using a network include:

Facilitating communications

Sharing hardware

Sharing data and information

Sharing software

Transferring funds.

6.2.1 TYPES OF NETWORK

A network is basically all of the components (hardware and software) involved in connecting computers across small and large distances .

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LAN

NETWORK

WAN MAN

LOCAL AREA NETWORK (LAN)

Local area networks (LANs) are used to connect networking devices that are in a very close geographic area, such as a floor of a building, a building itself, or a campus environment. A local

area network (LAN) is a computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. Typical LANs are created with Ethernet or

WIFI networking connections, and are wholly owned by a single person, group, or company.

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Types of LAN

Personal area network

(PAN)

LAN

House area network

(HAN)

Personal Area Network

A personal area network (PAN) is a computer network used for communication among computer and different information technological devices close to one person. Headphone Smartphone

Laptop PDA Mouse Printer

Examples of devices that are used in a PAN are:

Personal computers

Printers

Fax machines

Telephones

PDAs

Scanners

Video game consoles

A wired PAN is usually constructed with USB and Fire wire connections . Technologies such as

Bluetooth and infrared communication typically form a wireless PAN.

Home Area Network

A home area network (HAN) is a residential LAN which is used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices.

An important function is the sharing of Internet access, often a broadband service through a

Digital Subscriber Line (DSL) provider.

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Major Characteristics of LAN

Every computer has the potential to communicate with any other computers of the network

High degree of interconnection between computers

Easy physical connection of computers in a network

Inexpensive medium of data transmission

High data transmission rate

Advantages

The reliability of network is high because the failure of one computer in the network does not affect the functioning for other computers.

Addition of new computer to network is easy.

High rate of data transmission is possible.

Peripheral devices like magnetic disk and printer can be shared by other computers.

Disadvantages

If the communication line fails, the entire network system breaks down.

Uses of LAN

Followings are the major areas where LAN is normally used for:

File transfers and Access

Word and text processing

Electronic message handling

Remote database access

Personal computing

Digital voice transmission and storage

METROPOLITAN AREA NETWORK (MAN)

A metropolitan area network (MAN) is a large computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks (LANs) using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks (or WAN) and the Internet . Many of the same technologies and

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communications protocols found in local area networks and wide area networks are used to create metropolitan area networks.

A data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs) , but smaller than wide-area networks (WANs) . MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media. In MAN, different LANs are connected through a local telephone exchange. Some of the widely used protocols for MAN are RS-232, X.25, Frame Relay, Asynchronous Transfer Mode

(ATM), ISDN (Integrated Services Digital Network), OC·3 lines (1.55 Mbps), ADSL

(Asymmetrical Digital Subscriber Line) etc. These protocols are quite different from those used for LANs.

They can also provide interconnections between corporate data centers and Internet service providers. Almost all MANs are based on one of two basic forms of supporting technology:

SONET or Ethernet

There are three important features which discriminate MANs from LANs or WANs:

1. The network size falls intermediate between LANs and WANs. A MAN typically covers an area of between 5 and 50 km range. Many MANs cover an area the size of a city, although in some cases MANs may be as small as a group of buildings.

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2. A MAN (like a WAN) is not generally owned by a single organisation. The MAN, its communications links and equipment are generally owned by either a consortium of users or by a network service provider who sells the service to the users.

3. A MAN often acts as a high speed network to allow sharing of regional resources. It is also frequently used to provide a shared connection to other networks using a link to a WAN.

Types of MAN

Campus Area Network

MAN

Campus area network

(CAN)

A campus area network is a computer network made up of an interconnection of local area networks (LANs) within a limited geographical area.

In the case of a university campus-based campus network, the network is likely to link a variety of campus buildings including; academic departments, the university library and student residence halls.

Advantages

The biggest advantage of MANs is the bandwidth (potential speed) of the connecting links.

Efficiency and shared access.

All the computer-owning residents of the area have equal ability to go on line..

Some installations allow multiple users to share the same high-speed Internet connection, thereby sharing the cost of the service and securing a better quality of service through collective bargaining and economies of scale.

Disadvantages

It can be costly (hardware, software, support, etc.)

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Security problems

As the network consists of many computers over the span of a city, the connection can lag or become quite slow.

WIDE AREA NETWORK (WAN)

A WAN is a computer network which is used to transfer data over large geographical areas, such as, a country, continent, or the entire world. Typically, a WAN consists of two or more local-area networks (LANs) . Computers connected to a wide-area network are often connected through public networks, such as the telephone system. This ensures that computers and users in one location can communicate with computers and users in other locations. They can also be connected through leased lines or satellites. These leased lines involve a direct point-to-point connection between two sites. Point-to-point WAN service may involve either analog dial-up lines or dedicated leased digital private lines. The largest WAN in existence is the Internet .

A major factor impacting WAN design and performance is a requirement that they lease communications circuits from telephone companies or other communications carriers.

Transmission rates are typically 2 Mbps, 34 Mbps, 45 Mbps, 155 Mbps, 625 Mbps (or sometimes considerably more).

A wide area network allows long transmission of data, voice, image and video information. A

WAN is larger than a MAN network .

WAN are of 2 types:-

Public WAN - Public Wide Area Network are those network in which the data and information (resources) are access and shared publicly example Internet.

Private WAN - Private Wide Area Network are those network in which the data and information (resources) are access and shared privately example ARPANET.

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Major characteristics of WANs:

WANs generally connect devices that are separated by a broader geographical area

WANs use the services such as telephone companies, cable companies, satellite systems, and network providers.

WANs use serial connections of various types to provide access to bandwidth over large geographic area.

Advantages of WANs:

These are similar to those of LAN's except the scale of sharing etc. becomes far greater and can be world-wide.

Disadvantages of WANs:

Security become even more important as potential hackers could break into a computer system from anywhere in the world.

Encryption of secure data such as financial transactions is necessary because it is even easier to intercept data.

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Comparisons between LAN, MAN, WAN

Cost Network size

LAN

MAN

WAN

Low

High

Higher

Small

Larger

Largest

Speed

Fastest

Slower

Slowest

Number of computers

Smallest

Large

Largest

6.2.2 NETWORK TOPOLOGY

Network Topology refers to layout of a network and how different nodes in a network are connected to each other and how they communicate. This slideshow describes five of the most common network topologies.

1. Mesh Topology

In a mesh network, devices are connected with many redundant interconnections between network nodes. In a true mesh topology every node has a connection to every other node in the network. There are two types of mesh topologies:

Full mesh topology: occurs when every node has a circuit connecting it to every other node in a network. Full mesh is very expensive to implement but yields the greatest amount of redundancy, so in the event that one of those nodes fails, network traffic can be directed to any of the other nodes. Full mesh is usually reserved for backbone networks.

Partial mesh topology: is less expensive to implement and yields less redundancy than full mesh topology. With partial mesh, some nodes are organized in a full mesh scheme but others

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are only connected to one or two in the network. Partial mesh topology is commonly found in peripheral networks connected to a full meshed backbone.

2. Star Topology

In a star network devices are connected to a central computer, called a hub. Nodes communicate across the network by passing data through the hub.

Advantage:

In a star network, one malfunctioning node doesn't affect the rest of the network.

Disadvantage:

If the central computer fails, the entire network becomes unusable.

3. Bus Topology

In networking a bus is the central cable -- the main wire -- that connects all devices on a localarea network ( LAN ). It is also called the backbone. This is often used to describe the main network connections composing the Internet. Bus networks are relatively inexpensive and easy to install for small networks. Ethernet systems use a bus topology.

Advantage:

It's easy to connect a computer or device and typically it requires less cable than a star topology.

Disadvantage:

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The entire network shuts down if there is a break in the main wire and it can be difficult to identify the problem if the network shuts down.

4. Ring Topology

A local-area network ( LAN ) whose topology is a ring. That is, all of the nodes are connected in a

Closed loop. Messages travel around the ring, with each node reading those messages addressed to it. One main advantage to a ring network is that it can span larger distances than other types of networks, such as bus networks, because each node regenerates messages as they pass through it.

5. Tree Topology

This is a "hybrid" topology that combines characteristics of linear bus and star topologies. In a tree network, groups of star-configured networks are connected to a linear bus backbone cable.

Advantage:

A Tree topology is a good choice for large computer networks as the tree topology "divides" the whole network into parts that are more easily manageable.

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Disadvantage:

The entire network depends on a central hub and a failure of the central hub can cripple the whole network.

Check Your Progress – 2

a) ……………………. is the practice of linking two or more computing devices together for the purpose of sharing data.

b) …………………. networks are more suitable for larger networks.

c) A …………………….. is a computer network that spans a relatively small area.

d) A data network designed for a town or city is …………………….

6.3 COMPUTER CRIME AND SECURITY

Learning Objective :-

After studying this sub unit you would be able to – i. Explain what is computer crime ii. Understand its security

Computer crime or Cybercrime, refers to any crime that involves a computer and a network .

The computer may have been used in the commission of a crime, or it may be the target.

Dr. Debarati Halder and Dr. K. Jaishankar (2011) define Cybercrimes as:

"Offences that are committed against individuals or groups of individuals with a criminal motive to intentionally harm the reputation of the victim or cause physical or mental harm to the victim directly or indirectly, using modern telecommunication networks such as Internet (Chat rooms, emails, notice boards and groups) and mobile phones (SMS/MMS)"

Issues surrounding these types of crimes have become high-profile, particularly those surrounding cracking , copyright infringement , child pornography , and child grooming . There are also problems of privacy when confidential information is lost or intercepted, lawfully or otherwise.

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Crime committed using a computer and the internet to steal a person‘s identity or illegal imports or malicious programs cybercrime is nothing but where the computer used as an object or subject of crime

The first recorded cyber crime took place in the year1820. That is not surprising considering the fact that the abacus, which is thought to be the earliest form of a computer, has been around since

3500 B.C.

Categorizes Of Cyber Crime

The Computer as a Target: using a computer to attack other computers.

The computer as a weapon: using a computer to commit real world crimes .

Types of Cyber attacks, by percentage (source- FBI)

Financial fraud: 11%

Sabotage of data/networks: 17%

Theft of proprietary information: 20%

System penetration from the outside: 25%

Denial of service: 27%

Unauthorized access by insiders: 71%

Employee abuse of internet privileges 79%

Viruses: 85%

Types of Cyber Crime

Hacking: Hacking in simple terms means an illegal intrusion into a computer system and/or network. It is also known as CRACKING. Government websites are the hot targets of the hackers due to the press coverage, it receives. Hackers enjoy the media coverage.

Denial of service attack: This is an act by the criminal, who floods the bandwidth of the victims network or fills his e-mail box with spam mail depriving him of the services he is entitled to access or provide

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Virus dissemination: Malicious software that attaches itself to other software.(virus, worms, Trojan Horse, web jacking, e-mail bombing etc)

Computer vandalism: Damaging or destroying data rather than stealing or misusing them is called cyber vandalism. Transmitting virus: These are programs that attach themselves to a file and then circulate

Cyber terrorism: Terrorist attacks on the Internet is by distributed denial of service attacks, hate websites and hate emails, attacks on sensitive computer networks, etc.

Technology savvy terrorists are using 512-bit encryption, which is impossible to decrypt .

Software piracy: Theft of software through the illegal copying of genuine programs or the counterfeiting and distribution of products intended to pass for the original.

CYBER SECURITY:

Internet security is a branch of computer security specifically related to the Internet. Its objective is to establish rules and measure to use against attacks over the Internet.

Safety Tips:

Use antivirus software‘s

Insert firewalls

Uninstall unnecessary software

Maintain backup

Check security settings

Stay anonymous - choose a genderless screen name

Never give your full name or address to strangers

Learn ‗inetiquette - follow it and expect it from others

Don‘t respond to harassing or negative messages (flames)

Get out of uncomfortable or hostile situations quickly

Save offending messages

Learn more about Internet privacy

Advantages of cyber security:

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The cyber security will defend us from critical attacks.

It helps us to browse the safe website.

Internet security processes all the incoming and outgoing data on our computer.

Security will defend from hacks and virus.

The application of cyber security used in our PC needs update every week.

The security developers will update their database every week once. Hence the new virus also deleted.

Check Your Progress – 3

a) ………………………. refers to any crime that involves a computer and a network .

b) …………………… in simple terms means an illegal intrusion into a computer system and/or network.

c) ………………….. will defend from critical attacks

6.4 APPLICATION IN DEVELOPMENT SECTOR

Learning Objective :-

After studying this sub unit you would be able to – i. Define the application of internet in development sector

Internet is interconnection of large number of heterogeneous computer networks all over the world that can share information back and forth. These interconnected network exchange information by using same standards and protocols

Applications of internet

The internet is treated as one of the biggest invention. It has a large number of uses.

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Communication: It is used for sending and receiving message from one and other through internet by using electronic mail. Some of the web sites providing this service are yahoomail.com Hotmail.com rediffmail.com etc

Job searches: Getting information regarding availability of job in different sectors and areas.

You can publish your resume in online for prospective job. Some of the web sites providing this service are naukri.com, monster.com, summerjob.com, recuritmentindia.com etc.

Finding books and study material: Books and other study material stored around the world can be easily located through internet. Latest encyclopedias are available online.

Health and medicine: Internet provides information and knowledge about field of health medicine, people can have information about various diseases and can receive help .patient can be taken to virtual check room where they can meet doctors.

Travel: One can use internet to gather information about various tourist place. It can be used for booking Holiday tours, hotels, train and flights. Some of the web sites providing this service areindiatravelog.com, rajtravel.com, makemytrip.com.

Entertainment: Entertainment one can download jokes, songs movies, latest sports updates through internet. Some of the web sites providing this service arecricinfo.com, movies.com espn.com

Shopping: Internet is also used for online shopping. By just giving accounts details you can perform the transaction. You can even pay your bills and perform bank related transaction.

Stock market updates: You can sell or buy shares while sitting on computer through internet.

Several websites like ndtvprofit.com, moneypore.com, provide information regarding investment

Research: A large number of people are using internet for research purposes you can download any kind information by using internet

Business use of internet: Different ways by which internet can be used for business are:

Information about the product can be provided can be provided online to the customer.

Provide market information to the business

It helps business to recruit talented people

Help in locating suppliers of the product

Fast information regarding customers view about company product

Eliminate middle men and have a direct contact with customer

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Providing information to the investor by providing companies back ground and financial information on web site

Check Your Progress – 4

a) ……………… is used for sending and receiving message from one and other through internet by using electronic mail.

b) One can use internet to gather …………………… about various tourist place.

c) Internet is also used for ……………. shopping.

Let Us Sum Up (Summary)

a) A network is a group of connected communicating devices such as computers and printers.

The Internet is a collection of networks connected by interconnecting devices.

b) The words ―Browsing‖ or ―Surfing‖ are used to describe the process of looking at documents, websites and web pages on the Internet

c) A browser is software that is used to access the internet.

d) One of the most popular internet services is electronic mail (e – mail).

e) Outlook Express is an email program that works with Internet Explore versions 4.0 to

6.0.

f) Web-enabled content is content that can be accessed with a web browser or via HTTP or

HTTPS protocols.

g) Multimedia means that computer information can be represented through audio, video, and animation in addition to traditional media (i.e., text, graphics drawings, and images).

h) Networking is the practice of linking two or more computing devices together for the purpose of sharing data.

i) Peer-to-peer networks are more commonly implemented where less than ten computers are involved and where strict security is not necessary.

j) Client/server networks are more suitable for larger networks.

k) Network Topology refers to layout of a network .

l) A local area network (LAN) is a computer network that spans a relatively small area.

LAN are of two types personal area network and home area network.

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m) The various types of network topologies are Mesh, star, bus, ring and tree topology.

n) Crime committed using a computer and the internet to steal a person‘s identity or illegal imports or malicious programs cybercrime is nothing but where the computer used as an object or subject of crime.

o) Internet security is a branch of computer security specifically related to the Internet. Its objective is to establish rules and measure to use against attacks over the Internet.

Answers

Check Your Progress – 1

a) Networks

b) Browser

c) Ray Tomlinson

d) Web – enabled

e) Multimedia

Check Your Progress – 2

a) Networking

b) Client/server

c) Local area network

d) Metropolitan area network

Check Your Progress – 3

a) Computer crime

b) Hacking

c) Cyber security

Check Your Progress – 4

a) Internet

b) Information

c) Online

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