Glossary - Higher Ed
%SystemRoot% The path where the operating system is
10BaseT Ethernet LAN designed to run on twisted pair
cabling. 10BaseT runs at 10 megabits per second. The maximum length for the cabling between the NIC and the switch
(or hub, repeater, etc.) is 100 meters. It uses baseband signaling. No industry standard spelling exists, so sometimes it’s
written 10BASE-T or 10Base-T.
100BaseT Ethernet cabling system designed to run at 100
megabits per second on twisted pair cabling. It uses baseband signaling. No industry standard spelling exists, so
sometimes it’s written 100BASE-T or 100Base-T.
1000BaseT Gigabit Ethernet on UTP.
110 block The most common connection used with structured cabling, connecting horizontal cable runs with patch
16-bit (PC Card) Type of PC Card that can have up to two
distinct functions or devices, such as a modem/network card
2.1 speaker system Speaker setup consisting of two stereo
speakers combined with a subwoofer.
3.5-inch floppy drive Size of all modern floppy disk
drives; the format was introduced in 1986 and is one of the
longest surviving pieces of computer hardware.
34-pin ribbon cable Type of cable used by floppy disk
3-D graphics Video technology that attempts to create
images with the same depth and texture as objects seen in the
real world.
40-pin ribbon cable PATA cable used to attach EIDE
devices (such as hard drives) or ATAPI devices (such as optical drives) to a system. (See PATA.)
5.1 speaker system Speaker setup consisting of four satellite speakers plus a center speaker and a subwoofer.
64-bit processing A type of processing that can run a
compatible 64-bit operating system, such as Windows 7, and
64-bit applications. 64-bit PCs have a 64-bit-wide address
bus, enabling them to use more than 4 GB of RAM.
8.3 naming system File-naming convention that specified
a maximum of eight characters for a filename, followed by
a three-character file extension. Has been replaced by LFN
(long filename) support.
80-wire ribbon cable PATA cable used to attach fast EIDE
devices (such as ATA/100 hard drives) or ATAPI devices
(such as optical drives) to a system. (See PATA.)
802.11a Wireless networking standard that operates in
the 5-GHz band with a theoretical maximum throughput of
54 Mbps.
802.11b Wireless networking standard that operates in the
2.4-GHz band with a theoretical maximum throughput of
11 Mbps.
802.11g Wireless networking standard that operates in the
2.4-GHz band with a theoretical maximum throughput of 54
Mbps and is backward compatible with 802.11b.
802.11n Wireless networking standard that can operate
in both the 2.4-GHz and 5-GHz bands and uses multiple
in/multiple out (MIMO) to achieve a theoretical maximum
throughput of 100+ Mbps.
A/V sync Process of synchronizing audio and video.
AC (alternating current) Type of electricity in which the
flow of electrons alternates direction, back and forth, in a
AC’97 Sound card standard for lower-end audio devices;
created when most folks listened to stereo sound at best.
accelerometer Feature in smartphones and tablets that
rotates the screen when the device is physically rotated.
access control Security concept using physical security,
authentication, users and groups, and security policies.
ACPI (Advanced Configuration and Power Interface) Power management specification that far surpasses its predecessor, APM, by providing support for hot-swappable
devices and better control of power modes.
Action Center A one-page aggregation of event messages,
warnings, and maintenance messages in Windows 7.
activation Process of confirming that an installed copy of a
Microsoft product (most commonly Windows or a Microsoft
Office application) is legitimate. Usually done at the end of
software installation.
active matrix Type of liquid crystal display (LCD) that
replaced the passive matrix technology used in most portable
computer displays. Also called TFT (thin film transistor).
active partition On a hard drive, primary partition that
contains an operating system.
active PFC (power factor correction) Circuitry built into
AGP (Accelerated Graphics Port) 32/64-bit expansion
PC power supplies to reduce harmonics.
slot designed by Intel specifically for video that runs at 66
MHz and yields a throughput of at least 254 Mbps. Later versions (2×, 4×, 8×) give substantially higher throughput.
activity light An LED on a NIC, hub, or switch that blinks
rapidly to show data transfers over the network.
ad hoc mode Decentralized wireless network mode, otherwise known as peer-to-peer mode, where each wireless node
is in meshed contact with every other node.
Add or Remove Programs Applet allowing users to manually add or remove a program to or from the system.
address bus Set of wires leading from the CPU to the
memory controller chip (traditionally the Northbridge) that
enables the CPU to address RAM. Also used by the CPU
for I/O addressing. On current CPUs with built-in memory
controllers, the address bus refers to the internal electronic
channel from the microprocessor to RAM, along which the
addresses of memory storage locations are transmitted. Like
a post office box, each memory location has a distinct number
or address; the address bus provides the means by which the
microprocessor can access every location in memory.
address space Total amount of memory addresses that an
address bus can contain.
administrative shares Administrator tool to give local
algorithm Set of rules for solving a problem in a given
number of steps.
ALU (arithmetic logic unit) CPU logic circuits that perform basic arithmetic (add, subtract, multiply, and divide).
AMD (Advanced Micro Devices) CPU and chipset manufacturer that competes with Intel. Produces the popular Phenom, Athlon, Sempron, Turion, and Duron microprocessors;
also produces video card processors under its ATI brand.
AMI (American Megatrends, Inc.) Major producer of
BIOS software for motherboards, as well as many other computer-related components and software.
amperes (amps or A) Unit of measure for amperage, or
electrical current.
amplitude Loudness of a sound card.
AMR (audio modem riser) Proprietary slot used on some
motherboards to provide a sound interference–free connection for modems, sound cards, and NICs.
admins access to hard drives and system root folders.
analog Device that uses a physical quantity, such as length
Administrative Tools Group of Control Panel applets,
or voltage, to represent the value of a number. By contrast,
digital storage relies on a coding system of numeric units.
including Computer Management, Event Viewer, and Reliability and Performance Monitor.
Android Smartphone and tablet OS created by Google.
administrator account User account, created when the OS
anti-aliasing In computer imaging, blending effect that
is first installed, that is allowed complete, unfettered access
to the system without restriction.
Administrators group List of members with complete
administrator privileges.
ADSL (asymmetric digital subscriber line) Fully digital,
dedicated connection to the telephone system that provides
average download speeds of 7 Mbps and upload speeds of
512 Kbps.
Advanced Encryption Standard (AES) A block cipher created in the late 1990s that uses a 128-bit block size and a 128-,
192-, or 256-bit key size. Practically uncrackable.
Advanced Startup Options menu Menu that can be
reached during the boot process that offers advanced OS
startup options, such as to boot to Safe Mode or boot into
Last Known Good Configuration.
adware Type of malicious program that downloads ads to
a user’s computer, generating undesirable network traffic.
Aero The Windows Vista/7 desktop environment. Aero
adds some interesting aesthetic effects such as window transparency and Flip 3D.
smoothes sharp contrasts between two regions—e.g., jagged lines or different colors. Reduces jagged edges of text or
objects. In voice signal processing, process of removing or
smoothing out spurious frequencies from waveforms produced by converting digital signals back to analog.
anti-static bag Bag made of anti-static plastic into which
electronics are placed for temporary or long-term storage.
Used to protect components from electrostatic discharge.
anti-static mat Special surface on which to lay electronics. These mats come with a grounding connection designed
to equalize electrical potential between a workbench and
one or more electronic devices. Used to prevent electrostatic
anti-static wrist strap Special device worn around the
wrist with a grounding connection designed to equalize electrical potential between a technician and an electronic device.
Used to prevent electrostatic discharge.
antivirus program Software designed to combat viruses by
either seeking out and destroying them or passively guarding against them.
API (application programming interface) Software definition that describes operating system calls for application
software; conventions defining how a service is invoked.
APIPA (Automatic Private IP Addressing) Feature
of Windows that automatically assigns an IP address to
the system when the client cannot obtain an IP address
APM (Advanced Power Management) BIOS routines that
enable the CPU to turn on and off selected peripherals.
app A program for a tablet or smartphone. Also, a program
written for Windows 8 Metro interface.
applet Generic term for a program in the Windows Control
organization of the components on the motherboard is called
the AT form factor.
ATA (AT Attachment) Type of hard drive and controller
designed to replace the earlier ST506 and ESDI drives without
requiring replacement of the AT BIOS—hence, AT attachment. These drives are more popularly known as IDE drives.
(See IDE.) The ATA/33 standard has drive transfer speeds up
to 33 MBps; the ATA/66 up to 66 MBps; the ATA/100 up to
100 MBps; and the ATA/133 up to 133 MBps. (See Ultra DMA.)
ATA/ATAPI-6 Also known as ATA-6 or “Big Drive.”
Replaced the INT13 extensions and allowed for hard drives
as large as 144 petabytes (144 million GB).
ATAPI (ATA Packet Interface) Series of standards that
Applications Name of the tab in Task Manager that lists
running applications.
enables mass storage devices other than hard drives to use
the IDE/ATA controllers. Popular with optical drives. (See
archive To copy programs and data onto a relatively
ATAPI-compliant Devices that utilize the ATAPI standard.
inexpensive storage medium (disk, tape, etc.) for long-term
archive attribute Attribute of a file that shows whether
the file has been backed up since the last change. Each time
a file is opened, changed, or saved, the archive bit is turned
on. Some types of backups turn off this archive bit to indicate
that a good backup of the file exists on tape.
ARP (Address Resolution Protocol) Protocol in the TCP/
IP suite used with the command-line utility of the same name
(arp) to determine the MAC address that corresponds to a
particular IP address.
ASCII (American Standard Code for Information Interchange) Industry-standard 8-bit characters used to define
text characters, consisting of 96 upper- and lowercase letters,
plus 32 nonprinting control characters, each of which is numbered. These numbers were designed to achieve uniformity
among computer devices for printing and the exchange of
simple text documents.
(See ATAPI.)
Athlon Name used for a popular series of CPUs manufactured by AMD.
attrib.exe Command used to view the specific properties
of a file; can also be used to modify or remove file properties,
such as read-only, system, or archive.
attributes Values in a file that determine the hidden, readonly, system, and archive status of the file.
ATX (Advanced Technology Extended) Popular motherboard form factor that generally replaced the AT form factor.
audio interface High-end external sound device used by
audio engineers and recording artists.
authentication Any method a computer uses to determine
who can access it.
authorization Any method a computer uses to determine
what an authenticated user can do.
aspect ratio Ratio of width to height of an object. Standard
television has a 4:3 aspect ratio.
autodetection Process through which new disks are auto-
ASR (Automated System Recovery) Windows XP tool
designed to recover a badly corrupted Windows system;
similar to the ERD in Windows 2000.
Automatic Private IP Addressing (APIPA) A networking
assertive communication Means of communication that is
not pushy or bossy but is also not soft. Useful in dealing with
upset customers as it both defuses their anger and gives them
confidence that you know what you’re doing.
AT (Advanced Technology) Model name of the secondgeneration, 80286-based IBM computer. Many aspects of
the AT, such as the BIOS, CMOS, and expansion bus, have
become de facto standards in the PC industry. The physical
matically recognized by the BIOS.
feature of operating systems that enables DHCP clients to
self-configure an IP address and subnet mask automatically
when a DHCP server isn’t available.
Automatic Updates Feature allowing updates to Windows
to be retrieved automatically over the Internet.
AutoPlay Windows XP/Vista/7 setting, along with autorun.inf, enabling Windows to automatically detect media
files and begin using them. (See autorun.inf.)
autorun.inf File included on some media that automatically launches a program or installation routine when the
media is inserted/attached to a system.
autosensing Used by better-quality sound cards to detect
a device plugged into a port and to adapt the features of
that port.
analogous to bits per second. Due to advanced modulation of baud cycles as well as data compression, this is no
longer true.
auto-switching power supply Type of power supply
bcdedit A command-line tool that enables you to view the
able to detect the voltage of a particular outlet and adjust
BCD store, which lists the Windows boot options.
Award Software Major brand of BIOS software for motherboards. Owned by Phoenix Technologies.
backlight One of three main components used in LCDs to
illuminate an image.
backside bus Set of wires that connects the CPU to Level 2
cache. First appearing in the Pentium Pro, all modern CPUs
have a backside bus. Some buses run at the full speed of the
CPU, whereas others run at a fraction. Earlier Pentium IIs, for
example, had backside buses running at half the speed of the
processor. (See also frontside bus and external data bus.)
Backup and Restore Center Windows Vista/7’s backup
utility (Windows 7 drops “Center” from the name). It offers
two options: create a backup or restore from a backup.
Backup or Restore Wizard Utility contained within Windows that allows users to create system backups and set system restore points.
Backup Utility (ntbackup) Windows XP’s tool for creating
and restoring backups.
ball mouse Input device that enables users to manipulate
a cursor on the screen by using a ball and sensors that detect
the movement and direction of the ball.
bandwidth Piece of the spectrum occupied by some form
of signal, such as television, voice, or fax data. Signals require
a certain size and location of bandwidth to be transmitted.
The higher the bandwidth, the faster the signal transmission,
allowing for a more complex signal such as audio or video.
Because bandwidth is a limited space, when one user is
occupying it, others must wait their turn. Bandwidth is also
the capacity of a network to transmit a given amount of data
during a given period.
bank Total number of SIMMs or DIMMs that can be
accessed simultaneously by the chipset. The “width” of the
external data bus divided by the “width” of the SIMM or
DIMM sticks. DIMM slots that must be populated to activate
dual- or triple-channel memory.
bar code reader Tool to read Universal Product Code
(UPC) bar codes.
basic disk Hard drive partitioned in the “classic” way
with a master boot record (MBR) and partition table. (See also
dynamic disks.)
baud One analog cycle on a telephone line. In the early
BD-R (Blu-ray Disc-Recordable) Blu-ray Disc format that
enables writing data to blank discs.
BD-RE (Blu-ray Disc-REwritable) Blu-ray Disc equivalent
of the rewritable DVD, allows writing and rewriting several
times on the same BD. (See Blu-ray Disc.)
BD-ROM Blu-ray Disc equivalent of a DVD-ROM or
CD-ROM. (See Blu-ray Disc.)
beep codes Series of audible tones produced by a motherboard during the POST. These tones identify whether the
POST has completed successfully or whether some piece
of system hardware is not working properly. Consult the
manual for your particular motherboard for a specific list of
beep codes.
binary numbers Number system with a base of 2, unlike
the number systems most of us use that have bases of 10
(decimal numbers), 12 (measurement in feet and inches), and
60 (time). Binary numbers are preferred for computers for
precision and economy. An electronic circuit that can detect
the difference between two states (on–off, 0–1) is easier and
more inexpensive to build than one that could detect the differences among ten states (0–9).
biometric device Hardware device used to support
authentication; works by scanning and remembering a
unique aspect of a user’s various body parts (e.g., retina, iris,
face, or fingerprint) by using some form of sensing device
such as a retinal scanner.
BIOS (basic input/output services) Classically, software
routines burned onto the system ROM of a PC. More commonly seen as any software that directly controls a particular
piece of hardware. A set of programs encoded in read-only
memory (ROM) on computers. These programs handle
startup operations and low-level control of hardware such as
disk drives, the keyboard, and monitor.
bit Single binary digit. Also, any device that can be in an on
or off state.
bit depth Number of colors a video card is capable of producing. Common bit depths are 16-bit and 32-bit, representing 65,536 colors and 16.7 million colors (plus an 8-bit alpha
channel for transparency levels), respectively.
BitLocker Drive Encryption Drive encryption software
offered in Windows Vista/7 Ultimate and Enterprise editions. BitLocker requires a special chip to validate hardware
status and to ensure that the computer hasn’t been hacked.
days of telephone data transmission, the baud rate was often
Bluetooth Wireless technology designed to create small
wireless networks preconfigured to do specific jobs, but not
meant to replace full-function networks or Wi-Fi.
Blu-ray Disc (BD) Optical disc format that stores 25 or 50
GB of data, designed to be the replacement media for DVD.
Competed with HD DVD.
boot To initiate an automatic routine that clears the memory, loads the operating system, and prepares the computer
for use. Term is derived from “pull yourself up by your
bootstraps.” PCs must do that because RAM doesn’t retain
program instructions when power is turned off. A cold boot
occurs when the PC is physically switched on. A warm boot
loads a fresh OS without turning off the computer, lessening
the strain on the electronic circuitry. To do a warm boot, press
the ctrl-alt-delete keys twice in rapid succession (the threefingered salute).
Boot Configuration Data (BCD) file File that contains
information about the various operating systems installed
on the system as well as instructions for how to actually load
(bootstrap) them.
boot sector First sector on a PC hard drive or floppy disk,
traffic between nodes on one network does not appear on the
other network. For example, an Ethernet bridge only looks at
the MAC address. Bridges filter and forward packets based
on MAC addresses and operate at Level 2 (Data Link layer)
of the OSI seven-layer model.
broadband Commonly understood as a reference to highspeed, always-on communication links that can move large
files much more quickly than a regular phone line.
broadcast A network transmission addressed for every
node on the network.
browser Program specifically designed to retrieve, interpret, and display Web pages.
BSoD (Blue Screen of Death) Infamous error screen that
appears when Windows encounters an unrecoverable error.
BTX (Balanced Technology eXtended) Motherboard
form factor designed as an improvement over ATX.
buffer underrun Inability of a source device to provide a
CD burner with a constant stream of data while burning a
CD-R or CD-RW.
track 0. The boot-up software in ROM tells the computer to
load whatever program is found there. If a system disk is
read, the program in the boot record directs the computer to
the root directory to load the operating system.
buffered/registered DRAM Usually seen in mother-
boot.ini Text file used during the boot process that pro-
puter system to perform erratically, produce incorrect results,
or crash. The term was coined when a real bug was found in
one of the circuits of one of the first ENIAC computers.
vides a list of all OSs currently installed and available for
ntldr (NT Loader). Also tells where each OS is located on the
system. Used in Windows XP and earlier Microsoft operating
boards supporting more than four sticks of RAM, required to
address interference issues caused by the additional sticks.
bug Programming error that causes a program or a com-
burn Process of writing data to a writable optical disc, such
as a DVD-R.
bootable disk Disk that contains a functional operating
system; can also be a floppy disk, USB thumb drive, or optical disc.
burn-in failure Critical failure usually associated with
manufacturing defects.
bootmgr Windows Vista/7’s Boot Manager.
tronic devices, enabling those devices to communicate. Also,
a network topology where computers all connect to a main
line called a bus cable.
bootrec A Windows Recovery Environment troubleshooting and repair tool that repairs the master boot record, boot
sector, or BCD store. It replaces the fixboot and fixmbr Recovery Console commands used in Windows XP and earlier
operating systems.
bootstrap loader Segment of code in a system’s BIOS that
scans for an operating system, looks specifically for a valid
boot sector, and, when one is found, hands control over to
the boot sector; then the bootstrap loader removes itself from
bps (bits per second) Measurement of how fast data is
bus Series of wires connecting two or more separate elec-
bus mastering Circuitry allowing devices to avoid ­conflicts
on the external data bus.
bus topology Network configuration wherein all computers connect to the network via a central bus cable.
byte Unit of 8 bits; fundamental data unit of personal computers. Storing the equivalent of one character, the byte is
also the basic unit of measurement for computer storage.
CAB files Short for cabinet files. These files are compressed
moved from one place to another. A 56K modem can move
~56,000 bits per second.
and most commonly used during OS installation to store
many smaller files, such as device drivers.
bridge A device that connects two networks and passes
cache (disk) Special area of RAM that stores the data most
frequently accessed from the hard drive. Cache memory can
optimize the use of your systems.
traffic between them based only on the node address, so that
cache (L1, L2, L3, etc.) Special section of fast memory,
usually built into the CPU, used by the onboard logic to store
information most frequently accessed by the CPU.
CD-R (CD-recordable) CD technology that accepts a single “burn” but cannot be erased after that one burn.
calibration Process of matching the print output of a
compact storage disc for audio or video data. CD-ROMs are
read by using CD-ROM drives and optical drives with backward compatibility, such as DVD and Blu-ray Disc drives.
printer to the visual output of a monitor.
capacitive touchscreen Type of touchscreen that uses
CD-ROM (compact disc/read-only memory) Read-only
electrical current in your body to determine movement of
your fingers across the screen.
CD-RW (CD-rewritable) CD technology that accepts mul-
card reader Device with which you can read data from one
of several types of flash memory.
Celeron Lower-cost brand of Intel CPUs.
card services Uppermost level of PCMCIA services. The
phones, smartphones, and other mobile devices to connect to
the Internet.
card services level recognizes the function of a particular PC
Card and provides the specialized drivers necessary to make
the card work. (See also socket services.)
CardBus 32-bit PC cards that can support up to eight
devices on each card. Electrically incompatible with earlier
PC cards (3.3 V versus 5 V).
CAT 5 Category 5 wire; a TIA/EIA standard for UTP wiring that can operate at up to 100 megabits per second.
CAT 5e Category 5e wire; TIA/EIA standard for UTP wir-
tiple reads/writes like a hard drive.
cellular wireless networks Networks that enable cell
Centrino Marketing name for an Intel laptop solution
including the mobile processor, support chips, and wireless
Centronics connector Connector used with older printers.
certification License that demonstrates competency in
some specialized skill.
Certified Cisco Network Associate (CCNA) One of the
ing that can operate at up to 1 gigabit per second.
certifications demonstrating a knowledge of Cisco networking products.
CAT 6 Category 6 wire; TIA/EIA standard for UTP wiring
that can operate at up to 10 gigabits per second.
chain of custody A documented history of who has been
CAT 6a Category 6a wire; augmented CAT 6 UTP wiring
that supports 10GBaseT networks at the full 100 meter distance between a node and a switch.
catastrophic failure Describes a failure in which a component or whole system will not boot; usually related to a manufacturing defect of a component. Could also be caused by
overheating and physical damage to computer components.
CCFL (cold cathode fluorescent lamp) Light technology
used in LCDs and flatbed scanners. CCFLs use relatively
little power for the amount of light they provide.
cd (chdir) Shorthand for “change directory.” Allows you to
change the focus of the command prompt from one directory
to another.
CD (compact disc) Originally designed as the replacement
for vinyl records, has become the primary method of longterm storage of music and data.
CD quality Audio quality that has a sample rate of 44.4
KHz and a bit rate of 128 bits.
CDDA (CD-Digital Audio) Special format used for early
CD-ROMs and all audio CDs; divides data into variablelength tracks. A good format to use for audio tracks but terrible for data because of lack of error checking.
in possession of a system.
CHAP (Challenge Handshake Authentication Protocol) Common remote access protocol; the serving system challenges the remote client, usually by means of asking for a
chassis intrusion detection Feature offered in some chassis that trips a switch when the chassis is opened.
chipset Electronic chips, specially designed to work
together, that handle all of the low-level functions of a PC. In
the original PC, the chipset consisted of close to 30 different
chips; today, chipsets usually consist of one, two, or three
separate chips embedded into a motherboard.
chkdsk (CheckDisk) Hard drive error detection and, to
a certain extent, correction utility in Windows. Originally
a DOS command (chkdsk.exe); also the executable for the
graphical Error-checking tool.
clean installation Installing an operating system on a fresh
drive, following a reformat of that drive. Often it’s the only
way to correct a problem with a system when many of the
crucial operating system files have become corrupted.
cleaning kit Method for cleaning floppy or optical drives.
client Computer program that uses the services of another
computer program. Also, software that extracts information
from a server; your auto-dial phone is a client, and the phone
company is its server. Also, a machine that accesses shared
resources on a server.
client/server Relationship in which client software obtains
services from a server on behalf of a person.
client/server network Network that has dedicated server
machines and client machines.
clock cycle Single charge to the clock wire of a CPU.
clock-multiplying CPU CPU that takes the incoming clock
code names Names that keep track of different variations
within CPU models.
codec (compressor/decompressor) Software that compresses or decompresses media streams.
color depth Term to define a scanner’s ability to produce
color, hue, and shade.
COM port(s) Serial communications ports available on
your computer.
signal and multiples it inside the CPU to let the internal circuitry of the CPU run faster.
command A request, typed from a terminal or embedded
in a file, to perform an operation or to execute a particular
clock speed Speed at which a CPU executes instructions,
command-line interface User interface for an OS devoid
measured in MHz or GHz. In modern CPUs, the internal
speed is a multiple of the external speed. (See also clock­multiplying CPU.)
of all graphical trappings.
clock (CLK) wire A special wire that, when charged, tells
the CPU that another piece of information is waiting to be
closed source Software that is solely controlled by its creator or distributor.
cluster Basic unit of storage on a floppy or hard disk. Multiple sectors are contained in a cluster. When Windows stores
a file on a disk, it writes those files into dozens or even hundreds of contiguous clusters. If there aren’t enough contiguous open clusters available, the operating system finds the
next open cluster and writes there, continuing this process
until the entire file is saved. The FAT or MFT tracks how the
files are distributed among the clusters on the disk.
CMOS (complementary metal-oxide semiconductor) Originally, the type of nonvolatile RAM that held information about the most basic parts of your PC, such as hard
drives, floppies, and amount of DRAM. Today, actual CMOS
chips have been replaced by flash-type nonvolatile RAM. The
information is the same, however, and is still called CMOS—
even though it is now almost always stored on Flash RAM.
command prompt Text prompt for entering commands.
CompactFlash (CF) One of the older but still popular flash
media formats. Its interface uses a simplified PC Card bus, so
it also supports I/O devices.
compatibility modes Feature of Windows 2000 and
beyond to allow software written for previous versions of
Windows to operate in newer operating systems.
compliance Concept that members of an organization
must abide by the rules of that organization. For a technician,
this often revolves around what software can or cannot be
installed on an organization’s computer.
component failure Occurs when a system device fails due
to a manufacturing or some other type of defect.
Component Services Programming tools in Windows for
the sharing of data objects between programs.
compression Process of squeezing data to eliminate
redundancies, allowing files to use less space when stored or
CMOS setup program Program enabling you to access and
CompTIA A+ 220-801 One half of the CompTIA A+ certification for PC technicians. The 801 exam focuses primarily
on hardware and networking.
update CMOS data.
CompTIA A+ 220-802 The second half of the CompTIA
CNR (communications and networking riser) Propri-
A+ certification for PC technicians. The 802 exam focuses primarily on software, security, and troubleshooting.
etary slot used on some motherboards to provide a sound
interference–free connection for modems, sound cards,
and NICs.
coaxial cable Cabling in which an internal conductor is
CompTIA A+ certification Industry-wide, vendor-neutral
computer certification program that demonstrates competency as a computer technician.
surrounded by another, outer conductor, thus sharing the
same axis.
CompTIA Network+ certification Industry-wide, vendor-
code Set of symbols representing characters (e.g., ASCII
code) or instructions in a computer program (a programmer
writes source code, which must be translated into executable
or machine code for the computer to use).
Computer Default interface in Windows Vista and Win-
neutral certification for network technicians, covering network hardware, installation, and troubleshooting.
dows 7 for Windows Explorer; displays hard drives and
devices with removeable storage. (See My Computer.)
computer administrator One of three types of user
accounts in Windows XP, has access to all resources on the
computer. A member of the local Administrators group.
Computer Management Applet in Windows’ Administrative Tools that contains several useful snap-ins, such as
Device Manager and Disk Management.
computing process Four parts of a computer’s operation:
input, processing, output, and storage.
Computing Technology Industry Association (CompTIA) Nonprofit IT trade association that administers the
CompTIA A+, CompTIA Network+ exams and many other
vendor-neutral IT certification exams.
conditioning charger Battery charger that contains intelligent circuitry that prevents portable computer batteries from
being overcharged and damaged.
connectors Small receptacles used to attach cables to a
system. Common types of connectors include USB, PS/2,
and DB-25.
computer. CPUs are known by names such as Core i5 and
Phenom II.
CRC (cyclic redundancy check) Very accurate mathematical method used to check for errors in long streams of transmitted data. Before data is sent, the main computer uses the
data to calculate a CRC value from the data’s contents. If the
receiver calculates from the received data a different CRC
value , the data was corrupted during transmission and is
re-sent. Ethernet packets use the CRC algorithm in the FCS
portion of the frame.
C-RIMM or CRIMM (continuity RIMM) Passive device
added to populate unused banks in a system that uses Rambus RIMMs.
crimper A specialized tool for connecting UTP wires to an
RJ-45 connector. Also called a crimping tool.
CrossFire Technology that combines the power of multiple
AMD graphics cards in a system.
crossover cable Special UTP cable used to connect hubs
paper, ink, ribbons, and toner cartridges.
or to connect network cards without a hub. Crossover cables
reverse the sending and receiving wire pairs from one end to
the other.
container file File containing two or more separate, com-
CRT (cathode ray tube) Tube of a monitor in which rays
consumables Materials used up by printers, including
pressed tracks, typically an audio track and a moving-picture
track. Also known as a wrapper.
context menu Small menu brought up by right-clicking on
objects in Windows.
Control Panel Collection of Windows applets, or small
of electrons are beamed onto a phosphorescent screen to
produce images. Also, a shorthand way to describe a monitor
that uses CRT rather than LCD technology.
CSMA/CA (carrier sense multiple access/collision avoidance) Networking scheme used by wireless devices to
programs, that can be used to configure various pieces of
hardware and software in a system.
transmit data while avoiding data collisions, which wireless
nodes have difficulty detecting.
controller card Card adapter that connects devices, such as
CSMA/CD (carrier sense multiple access/collision detection) Networking scheme used by Ethernet devices
a disk drive, to the main computer bus/motherboard.
convergence Measure of how sharply a single pixel
appears on a CRT; a monitor with poor convergence produces images that are not sharply defined.
copy backup Type of backup similar to a normal or full
backup, in that all selected files on a system are backed up.
This type of backup does not change the archive bit of the
files being backed up.
copy command Command in the command-line interface
for making a copy of a file and pasting it in another location.
Core Name used for the family of Intel CPUs that succeeded the Pentium 4.
counter Used to track data about a particular object when
using the Performance console in Windows XP.
CPU (central processing unit) “Brain” of the computer.
Microprocessor that handles primary calculations for the
to transmit data and resend data after detection of data
cylinder Single track on all the platters in a hard drive.
Imagine a hard drive as a series of metal cans, nested one
inside another; a single can would represent a cylinder.
daily backup Backup of all files that have been changed on
that day without changing the archive bits of those files. Also
called daily copy backup.
daisy-chaining Method of connecting several devices
along a bus and managing the signals for each device.
data classification System of organizing data according to
its sensitivity. Common classifications include public, highly
confidential, and top secret.
data roaming A feature of cellular data systems that
enables the signal to jump from cell tower to cell tower and
from your provider to another provider without obvious
del (erase) command Command in the command-line
data structure Scheme that directs how an OS stores and
retrieves data on and off a drive. Used interchangeably with
the term file system. (See also file system.)
desktop User’s primary interface to the Windows operating system.
DB connectors D-shaped connectors used for a variety of
the features of a full-fledged desktop computer but with a
much smaller footprint and lower weight.
connections in the PC and networking world. Can be male
(with prongs) or female (with holes) and have a varying
number of pins or sockets. Also called D-sub, D-subminiature, or D-shell connectors.
DB-15 connector A two- or three-row D-sub connector
(female) used for 10Base5 networks, MIDI/joysticks, and
analog video.
DB-25 connector D-sub connector (female), commonly
referred to as a parallel port connector.
DC (direct current) Type of electricity in which the flow of
electrons is in a complete circle in one direction.
DDR SDRAM (double data rate SDRAM) Type of DRAM
that makes two processes for every clock cycle. (See also
DDR2 SDRAM Type of SDRAM that sends 4 bits of data in
every clock cycle. (See also DDR SDRAM.)
DDR3 SDRAM Type of SDRAM that transfers data at twice
the rate of DDR2 SDRAM.
debug To detect, trace, and eliminate errors in computer
decibels Unit of measurement typically associated with
sound. The higher the number of decibels, the louder the
dedicated server Machine that is not used for any client
functions, only server functions.
default gateway In a TCP/IP network, the nearest router
to a particular host. This router’s IP address is part of the
necessary TCP/IP configuration for communicating with
multiple networks using IP.
definition file List of virus signatures that an antivirus
program can recognize.
defragmentation (defrag) Procedure in which all the files
on a hard disk are rewritten on disk so that all parts of each
file reside in contiguous clusters. The result is an improvement in disk speed during retrieval operations.
degauss Procedure used to break up the electromagnetic
fields that can build up on the cathode ray tube of a monitor;
involves running a current through a wire loop. Most monitors feature a manual degaussing tool.
interface used to delete/erase files.
desktop extender Portable computer that offers some of
desktop replacement Portable computer that offers the
same performance as a full-fledged desktop computer; these
systems are normally very heavy to carry and often cost
much more than the desktop systems they replace.
device driver Program used by the operating system
to control communications between the computer and
Device Manager Utility that enables techs to examine and
configure all the hardware and drivers in a Windows PC.
DHCP (Dynamic Host Configuration Protocol) Protocol
that enables a DHCP server to set TCP/IP settings automatically for a DHCP client.
differential backup Similar to an incremental backup.
Backs up the files that have been changed since the last
backup. This type of backup does not change the state of the
archive bit.
digital camera Camera that simulates film technology
digital certificate Form in which a public key is sent
from a Web server to a Web browser so that the browser can
decrypt the data sent by the server.
Digital Living Network Alliance (DLNA) devices Devices that connect to a home network, discover each other,
and share media. In theory, DLNA devices should work
with minimal setup or fuss, even if sourced from different
digital zoom Software tool to enhance the optical zoom
capabilities of a digital camera.
digitally signed driver A driver designed specifically to
work with Windows that has been tested and certified by
Microsoft to work stably with Windows.
digitizer A tablet that enables users to paint, ink, pencil, or
otherwise draw on a computer.
DIMM (dual inline memory module) 32- or 64-bit type of
DRAM packaging, similar to SIMMs, with the distinction that
each side of each tab inserted into the system performs a separate function. DIMMs come in a variety of sizes, with 184and 240-pin being the most common on desktop computers.
dipole antennas Standard straight-wire antennas that provide the most omnidirectional function.
diskpart A fully functioning command-line
partitioning tool.
dir command Command used in the command-line interface to display the entire contents of the current working
display adapter Handles all the communication between
directory Another name for a folder.
to adjust display settings, including resolution, refresh rate,
driver information, and color depth. (For the comparable tool
in Windows Vista, see Personalization applet.)
directory service Centralized index that each PC accesses
to locate resources in the domain.
DirectX Set of APIs enabling programs to control multimedia, such as sound, video, and graphics. Used in Windows
Vista and Windows 7 to draw the Aero desktop.
Disk Cleanup Utility built into Windows that can help
users clean up their disks by removing temporary Internet
files, deleting unused program files, and more.
disk cloning Taking a PC and making a duplicate of the
hard drive, including all data, software, and configuration files, and transferring it to another PC. (See image
the CPU and the monitor. Also known as a video card.
Display applet Tool in Windows XP and Windows 7 used
DisplayPort Digital video connector used by Apple Mac
desktop models and some PCs, notably from Dell. Designed
by VESA as a royalty-free connector to replace VGA and DVI.
DMA (direct memory access) modes Technique that
some PC hardware devices use to transfer data to and from
the memory without using the CPU.
DMA controller Resides between the RAM and the devices
and handles DMA requests.
DNS (domain name service) TCP/IP name resolution
system that translates a host name into an IP address.
disk duplexing Type of disk mirroring using two separate
controllers rather than one; faster than traditional mirroring.
DNS domain Specific branch of the DNS name space. First-
disk initialization A process that places special informa-
docking station Device that provides a portable computer
tion on every hard drive installed in a Windows system.
extra features such as a DVD drive or PC Card, in addition to
legacy and modern ports. Similar to a port replicator.
Disk Management Snap-in available with the Microsoft
Management Console that enables techs to configure the
various disks installed in a system; available in the Computer
Management Administrative Tool.
disk mirroring Process by which data is written simultaneously to two or more disk drives. Read and write speed is
decreased but redundancy in case of catastrophe is increased.
disk quota Application allowing network administrators
to limit hard drive space usage.
disk striping Process by which data is spread among multiple (at least two) drives. Increases speed for both reads and
writes of data. Considered RAID level 0 because it does not
provide fault tolerance.
disk striping with parity Method for providing fault tolerance by writing data across multiple drives and then including an additional drive, called a parity drive, that stores
information to rebuild the data contained on the other drives.
Requires at least three physical disks: two for the data and a
third for the parity drive. This provides data redundancy at
RAID levels 3–5 with different options.
disk thrashing Hard drive that is constantly being accessed
due to lack of available system memory. When system
memory runs low, a Windows system will utilize hard disk
space as “virtual” memory, thus causing an unusual amount
of hard drive access.
level DNS domains include .com, .gov, and .edu.
document findings, actions, and outcomes Recording
each troubleshooting job: what the problem was, how it was
fixed, and other helpful information. (One of the steps a technician uses to solve a problem.)
Documents folder Windows Vista/7 folder for storing
user-created files. Replaces the My Documents folder previously used in Windows 2000/XP. (See My Documents.)
Dolby Digital Technology for sound reductions and channeling methods used for digital audio.
domain Groupings of users, computers, or networks. In
Microsoft networking, a domain is a group of computers
and users that share a common account database and a common security policy. On the Internet, a domain is a group
of computers that share a common element in their hierarchical name. Other types of domains exist—e.g., broadcast
domain, etc.
domain-based network Network that eliminates the need
for logging on to multiple servers by using domain controllers to hold the security database for all systems.
DOS (Disk Operating System) First popular operating
system available for PCs. A text-based, single-tasking operating system that was not completely replaced until the introduction of Windows 95.
dot-matrix printer Printer that creates each character from
dual-channel memory Form of DDR, DDR2, and DDR3
an array of dots. Pins striking a ribbon against the paper,
one pin for each dot position, form the dots. May be a serial
printer (printing one character at a time) or a line printer.
memory access used by many motherboards that requires
two identical sticks of DDR, DDR2, or DDR3 RAM.
dot pitch Value relating to CRTs, showing the diagonal
distance between phosphors measured in millimeters.
double-sided RAM RAM stick with RAM chips soldered
to both sides of the stick. May only be used with motherboards designed to accept double-sided RAM. Very common.
dpi (dots per inch) Measure of printer resolution
that counts the dots the device can produce per linear
(horizontal) inch.
DPMS (display power-management signaling) Specification that can reduce CRT power consumption by 75 percent
by reducing/eliminating video signals during idle periods.
DRAM (dynamic random access memory or dynamic
RAM) Memory used to store data in most personal com-
dual-core CPUs that have two execution units on the same
physical chip but share caches and RAM.
dual-scan passive matrix Manufacturing technique for
increasing display updates by refreshing two lines at a time.
DualView Microsoft feature enabling Windows to use two
or more monitors simultaneously.
dumpster diving To go through someone’s trash in search
of information.
DUN (Dial-up Networking) Software used by Windows
to govern the connection between the modem and the ISP.
duplexing Similar to mirroring in that data is written to
and read from two physical drives, for fault tolerance. Separate controllers are used for each drive, both for additional
fault tolerance and for additional speed. Considered RAID
level 1. Also called disk duplexing or drive duplexing.
puters. DRAM stores each bit in a “cell” composed of a transistor and a capacitor. Because the capacitor in a DRAM cell
can only hold a charge for a few milliseconds, DRAM must
be continually refreshed, or rewritten, to retain its data.
of CPUs.
DriveLock CMOS program enabling you to control the
ATA security mode feature set. Also known as drive lock.
DVD (digital versatile disc) Optical disc format that provides for 4–17 GB of video or data storage.
driver signing Digital signature for drivers used by Windows to protect against potentially bad drivers.
DVD-ROM DVD equivalent of the standard CD-ROM.
DS3D (DirectSound3D) Introduced with DirectX 3.0,
DS3D is a command set used to create positional audio, or
sounds that appear to come from in front, in back, or to the
side of a user. Merged with DirectSound into DirectAudio in
DirectX 8. (See also DirectX.)
DSL (digital subscriber line) High-speed Internet connection technology that uses a regular telephone line for connectivity. DSL comes in several varieties, including asynchronous (ADSL) and synchronous (SDSL), and many speeds.
Typical home-user DSL connections are ADSL with a download speed of 7 Mbps and an upload speed of 512 Kbps.
Duron Lower-cost version of AMD’s Athlon series
DVD-RW/DVD+RW Incompatible rewritable DVD media
DVD-Video DVD format used exclusively to store digital
video; capable of storing over 2 hours of high-quality video
on a single DVD.
DVI (Digital Visual Interface) Special video connector
designed for digital-to-digital connections; most commonly
seen on PC video cards and LCD monitors. Some versions
also support analog signals with a special adapter.
dxdiag (DirectX Diagnostics Tool) Diagnostic tool for
D-subminiature See DB connectors.
getting information about and testing a computer’s DirectX
DTS (Digital Theatre Systems) Technology for sound
dye-sublimation printer Printer that uses a roll of heat-
reductions and channeling methods, similar to Dolby Digital.
dual boot Refers to a computer with two operating systems installed, enabling users to choose which operating
system to load on boot. Can also refer to kicking a device a
second time just in case the first time didn’t work.
dual-channel architecture Using two sticks of RAM
(either RDRAM or DDR) to increase throughput.
sensitive plastic film embedded with dyes, which are vaporized and then solidified onto specially coated paper to create
a high-quality image.
dynamic disks Special feature of Windows that enables
users to span a single volume across two or more drives.
Dynamic disks do not have partitions; they have volumes.
Dynamic disks can be striped, mirrored, and striped or mirrored with parity.
EAX (Environment Audio eXtensions) 3-D sound technology developed by Creative Labs but now supported by
most sound cards.
emulator Software or hardware that converts the commands to and from the host machine into an entirely different
ECC (error correction code) Special software, embedded on hard drives, that constantly scans the drives for bad
encryption Making data unreadable by those who do not
possess a key or password.
ECC RAM/DRAM (error correction code DRAM) RAM
that uses special chips to detect and fix memory errors.
Commonly used in high-end servers where data integrity
is crucial.
effective permissions User’s combined permissions
granted by multiple groups.
EFI (Extensible Firmware Interface) Firmware created by
Intel and HP that replaced traditional 16-bit BIOS and added
several new enhancements.
EFS (encrypting file system) Encryption tool found in
NTFS 5 and later.
EIDE (Enhanced IDE) Marketing concept of hard drive–
equipment rack A metal structure used in equipment
rooms to secure network hardware devices and patch panels.
Most racks are 19 inches wide. Devices designed to fit in such
a rack use a height measurement called units, or simply U.
erase lamp Component inside laser printers that uses light
to make the coating of the photosensitive drum conductive.
Error-checking Windows graphical tool that scans and
fixes hard drive problems. Often referred to by the name of
the executable, chkdsk, or Check Disk.
eSATA Serial ATA-based connector for external hard
drives and optical drives.
escalate Process used when person assigned to repair a
problem is not able to get the job done, such as sending the
problem to someone with more expertise.
maker Western Digital, encompassing four improvements
for IDE drives, including drives larger than 528 MB, four
devices, increase in drive throughput, and non–hard drive
devices. (See ATAPI, PIO mode.)
Establish a plan of action and implement the solution electric potential The voltage differential between any
Establish a theory of probable cause After identifying a
two objects, one of which is frequently ground or earth,
resulting in a degree of attraction for the electrons to move
from one of the objects to the other. A large difference
between a person and a doorknob, for example, can lead to
a shocking experience when the two touch. See electrostatic
discharge (ESD).
problem, techs question the obvious to determine what might
be the source of the problem. (One of the steps a technician
uses to solve a problem.)
electromagnetic interference (EMI) Electrical interference from one device to another, resulting in poor performance of the device being interfered with. Examples: Static
on your TV while running a blow dryer, or placing two monitors too close together and getting a “shaky” screen.
electrostatic discharge (ESD) Uncontrolled rush of electrons from one object to another. A real menace to PCs, as it
can cause permanent damage to semiconductors.
eliciting answers Communication strategy designed to
help techs understand a user’s problems better. Works by
listening to a user’s description of a problem and then asking
cogent questions.
e-mail (electronic mail) Messages, usually text, sent from
one person to another via computer. Can also be sent automatically to a group of addresses (mailing list).
emergency repair disk (ERD) Saves critical boot files and
partition information and is the main tool for fixing boot
problems in Windows 2000.
After establishing and testing a theory about a particular
problem, techs solve the problem. (One of the steps a technician uses to solve a problem.)
Ethernet Name coined by Xerox for the first standard of
network cabling and protocols. Based on a bus topology.
Ethic of Reciprocity Golden Rule: Do unto others as you
would have them do unto you.
EULA (End User License Agreement) Agreement that
accompanies a piece of software, to which the user must
agree before using the software. Outlines the terms of use for
the software and also lists any actions on the part of the user
that violate the agreement.
event auditing Feature of Event Viewer’s Security section
that creates an entry in the Security Log when certain events
happen, such as a user logging on.
Event Viewer Utility made available as an MMC snap-in
that enables users to monitor various system events, including network bandwidth usage and CPU utilization.
expand Command-line utility included with Windows
used to access files within CAB files.
expansion bus Set of wires going to the CPU, governed by
the expansion bus crystal, directly connected to expansion
slots of varying types (PCI, AGP, PCIe, etc.).
expansion bus crystal Controls the speed of the expansion bus.
expansion slots Connectors on a motherboard that enable
users to add optional components to a system. (See also AGP,
PCI, and PCIe.)
ExpressCard The high-performance serial version of the
PC Card that replaced PC Card slots on laptop PCs over the
past decade. ExpressCard comes in two widths: 34 mm and
54 mm, called ExpressCard/34 and ExpressCard/54.
extended partition Type of nonbootable hard disk partition. May only have one extended partition per disk. Purpose
is to divide a large disk into smaller partitions, each with a
separate drive letter.
Extensible Authentication Protocol (EAP) Authentication wrapper that EAP-compliant applications can use to
accept one of many types of authentication. While EAP is a
general-purpose authentication wrapper, its only substantial
use is in wireless networks.
FAT64 (exFAT) A Microsoft-proprietary file system that
breaks the 4-GB file-size barrier, supporting files up to 16
exabytes (EB) and a theoretical partition limit of 64 zettabytes
(ZB). Envisioned for use with flash media devices with a
capacity exceeding 2 TB.
FCS (Frame Check Sequence) Portion of an Ethernet
frame used for error checking, most commonly with the CRC
FDISK Disk-partitioning utility used in DOS and Windows
9x systems.
fiber-optic cable High-speed cable for transmitting data,
made of high-purity glass sealed within an opaque tube.
Much faster than conventional copper wire such as coaxial
file Collection of any form of data that is stored beyond the
time of execution of a single job. A file may contain program
instructions or data, which may be numerical, textual, or
graphical information.
extension Two, three, four, five or more letters that follow
file allocation unit Another term for cluster. (See also
a filename and identify the type of file. Common file extensions are .zip, .exe, .doc, .java, and .xhtml.
external data bus (EDB) Primary data highway of all
computers. Everything in your computer is tied either
directly or indirectly to the external data bus. (See also frontside bus and backside bus.)
Fast User Switching Account option that is useful when
multiple users share a system; allows users to switch without
logging off.
FAT (file allocation table) Hidden table that records
how files on a hard disk are stored in distinct clusters; the
only way DOS knows where to access files. Address of first
cluster of a file is stored in the directory file. FAT entry for
the first cluster is the address of the second cluster used to
store that file. In the entry for the second cluster for that file
is the address for the third cluster, and so on until the final
cluster, which gets a special end-of-file code. There are two
FATs, mirror images of each other, in case one is destroyed
or ­damaged. Also refers to the 16-bit file allocation table
when used by Windows 2000 and later NT-based operating
FAT16 File allocation table that uses 16 bits for addressing
file association Windows term for the proper program
to open a particular file; for example, the file association for
opening .MP3 files might be Winamp.
file format How information is encoded in a file. Two primary types are binary (pictures) and ASCII (text), but within
those are many formats, such as BMP and GIF for pictures.
Commonly represented by a suffix at the end of the filename;
for example, .txt for a text file or .exe for an executable.
file server Computer designated to store software, courseware, administrative tools, and other data on a LAN or
WAN. It “serves” this information to other computers via the
network when users enter their personal access codes.
file system Scheme that directs how an OS stores and
retrieves data on and off a drive; FAT32 and NTFS are both
file systems. Used interchangeably with the term “data structure.” (See also data structure.)
filename Name assigned to a file when the file is first written on a disk. Every file on a disk within the same folder
must have a unique name. Filenames can contain any character (including spaces), except the following: \ / : * ? “ < > |
clusters. Used as the primary hard drive format on DOS and
early Windows 95 machines; currently used with smaller (2
GB or less) capacity flash media devices.
Files and Settings Transfer Wizard Windows XP’s system
FAT32 File allocation table that uses 32 bits for addressing
work and the Internet.
clusters. Commonly used with Windows 98 and Windows
Me systems. Some Windows 2000 Professional and Windows
XP systems also use FAT32, although most modern Windows
systems use the more robust NTFS. Default format for flash
media devices larger than 2 GB.
for moving files and settings to a new PC.
firewall Device that restricts traffic between a local netFireWire (IEEE 1394) Interconnection standard to send
wide-band signals over a serialized, physically thin connector system. Serial bus developed by Apple and Texas
Instruments; enables connection of 63 devices at speeds up
to 800 megabits per second.
firmware Embedded programs or code stored on a ROM
fragmentation Occurs when files and directories get
chip. Generally OS-independent, thus allowing devices to
operate in a wide variety of circumstances without direct OS
support. The system BIOS is firmware.
jumbled on a fixed disk and are no longer contiguous. Can
significantly slow down hard drive access times and can be
repaired by using the defrag utility included with each version of Windows. (See also defragmentation.)
Flash ROM ROM technology that can be electrically reprogrammed while still in the PC. Overwhelmingly the most
common storage medium of BIOS in PCs today, as it can
be upgraded without a need to open the computer on most
frame A data unit transferred across a network. Frames
consist of several parts, such as the sending and receiving
MAC addresses, the data being sent, and the frame check
flatbed scanner Most popular form of consumer scanner;
freeware Software that is distributed for free, with no
runs a bright light along the length of the tray to capture an
license fee.
FlexATX Motherboard form factor. Motherboards built
in accordance with the FlexATX form factor are very small,
much smaller than microATX motherboards.
Flip 3D In the Aero desktop environment, a three­ imensional replacement for alt-tab. Accessed by pressing
the w
­ indows key-tab key combination.
floating point unit (FPU) Special CPU circuitry that handles complex numbers.
floppy disk Removable storage media that can hold
between 720 KB and 1.44 MB of data.
floppy drive System hardware that uses removable 3.5inch disks as storage media.
flux reversal Point at which a read/write head detects a
change in magnetic polarity.
FM synthesis Producing sound by electronic emulation of
various instruments to more-or-less produce music and other
sound effects.
Folders list A tree menu in Windows Explorer for Windows 2000 and XP that displays the file structure on the left
side of the window; toggled on with the Folders button. In
Windows Vista and 7, the Folders list is active by default.
form factor Standard for the physical organization of
frequency Measure of a sound’s tone, either high or low.
frontside bus Wires that connect the CPU to the main system RAM. Generally running at speeds of 66–133 MHz. Distinct from the expansion bus and the backside bus, though it
shares wires with the former.
front-view projector Shoots the image out the front and
counts on you to put a screen in front at the proper distance.
FRU (field replaceable unit) Any part of a PC that is considered to be replaceable “in the field,” i.e., a customer location. There is no official list of FRUs—it is usually a matter of
policy by the repair center.
FTP (File Transfer Protocol) Rules that enable two computers to talk to one another during a file transfer. Protocol
used when you transfer a file from one computer to another
across the Internet. FTP uses port numbers 20 and 21.
fuel cells Power source that uses chemical reactions to
produce electricity. Lightweight, compact, and stable devices
expected to replace batteries as the primary power source for
portable PCs.
full-duplex Any device that can send and receive data
Full-Speed USB USB standard that runs at 12 Mbps. Also
known as USB 1.1.
motherboard components and motherboard size. Most common form factors are ATX and BTX.
Function (fn) key Special key on many laptops that
enables some keys to perform a third duty.
format command Command in the command-line inter-
fuser assembly Mechanism in laser printers that uses two
face used to format a storage device.
rollers to fuse toner to paper during the print process.
formatting Magnetically mapping a disk to provide a
future-proofing Configuring a PC so that it will run programs (especially games) released in the coming years.
structure for storing data; can be done to any type of disk,
including a floppy disk, hard disk, or other type of removable disk.
FPU (floating point unit) Formal term for math coprocessor (also called a numeric processor) circuitry inside a CPU.
A math coprocessor calculates by using a floating point math
(which allows for decimals). Before the Intel 80486, FPUs
were separate chips from the CPU.
gain Ratio of increase of radio frequency output provided
by an antenna, measured in decibels (dB).
GDI (graphical device interface) Component of Windows
that utilizes the CPU rather than the printer to process a print
job as a bitmapped image of each page.
general protection fault (GPF) Error code usually seen
when separate active programs conflict on resources or data.
hang When a computer freezes and does not respond to
keyboard commands, it is said to “hang” or to have “hung.”
geometry Numbers representing three values: heads,
hang time Number of seconds a too-often-hung computer
is airborne after you have thrown it out a second-story
cylinders, and sectors per track; defines where a hard drive
stores data.
geotracking Feature in cellular phones that enables the
cell phone companies and government agencies to use the
ID or MAC address to pinpoint where your phone is at any
given time.
hard drive Data-recording system using solid disks
giga Prefix for the quantity 1,073,741,824 (230) or for 1 bil-
hardware Physical computer equipment such as electrical,
lion. One gigabyte would be 1,073,741,824 bytes, except with
hard drive labeling, where it means 1 billion bytes. One gigahertz is 1 billion hertz.
electronic, magnetic, and mechanical devices. Anything in
the computer world that you can hold in your hand. A floppy
drive is hardware; Microsoft Word is not.
Global Positioning System (GPS) Technology that enables
hardware profile Feature in Windows XP that enables the
a mobile device to determine where you are on a map.
user to switch several hardware configurations at once during the Windows boot process.
globally unique identifier (GUID) partition table (GPT) of magnetic material turning at high speeds to store and
retrieve programs and data in a computer. Abbreviated HDD
for hard disk drive.
Partitioning scheme that enables you to create more than four
primary partitions without needing to use dynamic disks.
hardware protocol Defines many aspects of a network,
from the packet type to the cabling and connectors used.
GPU (graphics processing unit) Specialized processor
that helps the CPU by taking over all of the 3-D rendering
HBA (host bus adapter) Connects SATA devices to the
grayscale depth Number that defines how many shades of
that defines high-resolution images and 5.1, 6.1, and 7.1
gray the scanner can save per dot.
grayware Program that intrudes into a user’s computer
experience without damaging any systems or data.
group Collection of user accounts that share the same
access capabilities.
Group Policy Means of easily controlling the settings of
multiple network clients with policies such as setting minimum password length or preventing Registry edits.
guest account Very limited built-in account type for Windows; a member of the Guest group.
GUI (graphical user interface) Interface that enables user
to interact with computer graphically, by using a mouse or
other pointing device to manipulate icons that represent
programs or documents, instead of using only text as in early
interfaces. Pronounced “gooey.”
gyroscope Device that can detect the position of the tablet
or phone in 3-D space.
HAL (hardware abstraction layer) Part of the Windows
OS that separates system-specific device drivers from the rest
of the NT system.
handshaking Procedure performed by modems, terminals,
and computers to verify that communication has been correctly established.
expansion bus. Also known as the SATA controller.
HD (Hi-Definition) Multimedia transmission standard
HDA (High Definition Audio) Intel-designed standard
to support features such as true surround sound with many
discrete speakers. Often referred to by its code name, Azalia.
HDD (hard disk drive) Data-recording system using solid
disks of magnetic material turning at high speeds to store
and retrieve programs and data in a computer.
HDMI (High Definition Multimedia Interface) Single
multimedia connection that includes both high-definition
video and audio. One of the best connections for outputting
to television. Also contains copy protection features.
head actuator Mechanism for moving the arms inside a
hard drive on which the read/write heads are mounted.
heads Short for read/write heads used by hard drives to
store data.
heat dope See thermal compound.
hex (hexadecimal) Base-16 numbering system using ten
digits (0 through 9) and six letters (A through F). In the computer world, shorthand way to write binary numbers by substituting one hex digit for a four-digit binary number (e.g.,
hex 9 = binary 1001).
hibernation Power management setting in which all data
from RAM is written to the hard drive before going to sleep.
Upon waking up, all information is retrieved from the hard
drive and returned to RAM.
hidden attribute File attribute that, when used, does not
allow the dir command to show a file.
hierarchical directory tree Method by which Windows
organizes files into a series of folders, called directories,
under the root directory. (See also root directory.)
high gloss Laptop screen finish that offers sharper contrast,
richer colors, and wider viewing angles than a matte finish,
but is also much more reflective.
high-level formatting Format that sets up a file system on
a drive.
HTTPS (HTTP over Secure Sockets Layer) Secure form
of HTTP used commonly for Internet business transactions or
any time when a secure connection is required. Uses port 443.
(See also HTTP.)
hub Electronic device that sits at the center of a star topology network, providing a common point for the connection
of network devices. Hubs repeat all information out to all
ports and have been replaced by switches, although the term
is still commonly used.
hybrid A network topology that combines features from
multiple other topologies, such as the star-bus topology.
high-voltage anode Component in a CRT monitor that has
very high voltages of electricity flowing through it.
hyperthreading CPU feature that enables a single pipeline
to run more than one thread at once.
Hi-Speed USB USB standard that runs at 480 Mbps. Also
hypervisor Software that enables a single computer to run
multiple operating systems simultaneously.
referred to as USB 2.0.
home screen The default “desktop” of a mobile device.
home server PC A computer built to store files on a small
office/home office (SOHO) network.
HomeGroup A Windows 7 feature that connects a group
of computers using a common password—no special user
names required. Each computer can be a member of only one
homegroup at a time. Homegroups enable simple sharing of
documents and printers between computers.
honesty Telling the truth—a very important thing for a
I/O (input/output) General term for reading and writing
data to a computer. “Input” includes data entered from a
keyboard, identified by a pointing device (such as a mouse),
or loaded from a disk. “Output” includes writing information to a disk, viewing it on a CRT, or printing it to a printer.
I/O addressing Using the address bus to talk to system
I/O advanced programmable interrupt controller
(IOAPIC) Typically located in the Southbridge, acts as the
tech to do.
traffic cop for interrupt requests to the CPU.
horizontal cabling Cabling that connects the equipment
I/O base address First value in an I/O address range.
room to the work areas.
host On a TCP/IP network, single device that has an IP
address—any device (usually a computer) that can be the
source or destination of a data packet. In the mainframe
world, computer that is made available for use by multiple
people simultaneously. Also, in virtualization, a computer
running one or more virtual operating systems.
hot-swappable Any hardware that may be attached to or
removed from a PC without interrupting the PC’s normal
HRR (horizontal refresh rate) Amount of time it takes for
a CRT to draw one horizontal line of pixels on a display.
HTML (Hypertext Markup Language) ASCII-based,
script-like language for creating hypertext documents such as
those on the World Wide Web.
HTPC A home theater PC designed to attach to a TV or
projector for movie and TV viewing.
HTTP (Hypertext Transfer Protocol) Extremely fast protocol used for network file transfers in the WWW environment. Uses port 80.
ICH (I/O Controller Hub) Official name for Southbridge
chip found in Intel’s chipsets.
icon Small image or graphic, most commonly found on a
system’s desktop, that launches a program when selected.
ICS (Internet Connection Sharing) Windows feature that
enables a single network connection to be shared among several machines. ICS was first introduced with Windows 98.
IDE (integrated drive electronics) PC specification for
small- to medium-sized hard drives in which the controlling
electronics for the drive are part of the drive itself, speeding
up transfer rates and leaving only a simple adapter (or “paddle”). IDE only supported two drives per system of no more
than 504 MB each, and has been completely supplanted by
Enhanced IDE. EIDE supports four drives of over 8 GB each
and more than doubles the transfer rate. The more common
name for PATA drives. Also known as intelligent drive electronics. (See PATA.)
identify the problem To question the user and find
out what has been changed recently or is no longer working properly. (One of the steps a technician uses to solve a
IEC-320 Connects the cable supplying AC power from a
installation disc Typically a CD-ROM or DVD that holds
wall outlet into the power supply.
all the necessary device drivers.
IEEE (Institute of Electronic and Electrical Engineers) instruction set All of the machine-language commands
Leading standards-setting group in the United States.
that a particular CPU is designed to understand.
IEEE 1284 IEEE standard governing parallel
integrated memory controller (IMC) Memory controller
circuitry built into the CPU. An IMC enables faster control
over things like the large L3 cache shared among multiple
IEEE 1394 IEEE standard governing FireWire communication. (See also FireWire.)
IEEE 1394a FireWire standard that runs at 400 Mbps.
IEEE 1394b FireWire standard that runs at 800 Mbps.
IEEE 802.11 Wireless Ethernet standard more commonly
known as Wi-Fi.
image deployment Operating system installation that uses
a complete image of a hard drive as an installation media.
Helpful when installing an operating system on a large number of identical PCs.
image file Bit-by-bit image of data to be burned on CD or
DVD—from one file to an entire disc—stored as a single file
on a hard drive. Particularly handy when copying from CD
to CD or DVD to DVD.
IMAP4 (Internet Message Access Protocol version 4) An alternative to POP3 that retrieves e-mail from an e-mail
server, like POP3; IMAP uses TCP port 143.
impact printer Uses pins and inked ribbons to print text or
images on a piece of paper.
impedance Amount of resistance to an electrical signal on
a wire. Relative measure of the amount of data a cable can
incident report Record of the details of an accident,
including what happened and where it happened.
integrity Always doing the right thing.
interface Means by which a user interacts with a piece of
Interrupt 13 (INT13) extensions Improved type of BIOS
that accepts EIDE drives up to 137 GB.
interrupt/interruption Suspension of a process, such as
the execution of a computer program, caused by an event
external to the computer and performed in such a way that
the process can be resumed. Events of this kind include sensors monitoring laboratory equipment or a user pressing an
interrupt key.
inverter Device used to convert DC current into AC. Commonly used with CCFLs in laptops and flatbed scanners.
iOS The operating system of Apple mobile devices.
IP address Numeric address of a computer connected to
the Internet. An IPv4 address is made up of four octets of
8-bit binary numbers translated into their shorthand numeric
values. An IPv6 address is 128 bits long. The IP address can
be broken down into a network ID and a host ID. Also called
Internet address.
ipconfig Command-line utility for Windows servers and
workstations that displays the current TCP/IP configuration
of the machine. Similar to winipcfg and ifconfig.
incremental backup Backs up all files that have their
archive bits turned on, meaning that they have been changed
since the last backup. Turns the archive bits off after the files
have been backed up.
IPsec (Internet Protocol security) Microsoft’s encryption
Information Technology (IT) Field of computers, their
IPv4 (Internet Protocol version 4) Internet standard pro-
operation, and their maintenance.
infrastructure mode Wireless networking mode that uses
one or more WAPs to connect the wireless network nodes to
a wired network segment.
inheritance NTFS feature that passes on the same permissions in any subfolders/files resident in the original folder.
ink cartridge Small container of ink for inkjet printers.
inkjet printer Uses liquid ink, sprayed through a series of
tiny jets, to print text or images on a piece of paper.
method of choice for networks consisting of multiple networks linked by a private connection, providing transparent
encryption between the server and the client.
tocol that provides a common layer over dissimilar networks;
used to move packets among host computers and through
gateways if necessary. Part of the TCP/IP protocol suite. Uses
the dotted-decimal format—
IPv6 (Internet Protocol version 6) Protocol in which
addresses consist of eight sets of four hexadecimal numbers,
each number being a value between 0000 and FFFF, using
a colon to separate the numbers. Here’s an example:
IrDA (Infrared Data Association) protocol Protocol
that enables communication through infrared devices, with
speeds of up to 4 Mbps.
IRQ (interrupt request) Signal from a hardware device,
keyboard Input device. Three common types of keyboards
such as a modem or a mouse, indicating that it needs the
CPU’s attention. In PCs, IRQs are sent along specific IRQ
channels associated with a particular device. IRQ conflicts
were a common problem in the past when adding expansion
boards, but the plug-and-play specification has removed this
headache in most cases.
exist: those that use a mini-DIN (PS/2) connection, those that
use a USB connection, and those that use wireless technology.
ISA (Industry Standard Architecture) Industry Standard
Architecture design was found in the original IBM PC for the
slots that allowed additional hardware to be connected to the
computer’s motherboard. An 8-bit, 8.33-MHz expansion bus
was designed by IBM for its AT computer and released to the
public domain. An improved 16-bit bus was also released to
the public domain. Replaced by PCI in the mid-1990s.
Knowledge Base Large collection of documents and FAQs
that is maintained by Microsoft. Found on Microsoft’s Web
site, the Knowledge Base is an excellent place to search for
assistance on most operating system problems.
KVM (keyboard, video, mouse) switch Hardware device
that enables multiple computers to be viewed and controlled
by a single mouse, keyboard, and screen.
LAN (local area network) Group of PCs connected via
cabling, radio, or infrared that use this connectivity to share
resources such as printers and mass storage.
ISDN (integrated services digital network) CCITT
(Comité Consultatif Internationale de Télégraphie et Téléphonie) standard that defines a digital method for communications to replace the current analog telephone system. ISDN
is superior to POTS telephone lines because it supports a
transfer rate of up to 128 Kbps for sending information from
computer to computer. It also allows data and voice to share
a common phone line. DSL reduced demand for ISDN substantially. (See also POTS.)
laptop Traditional clamshell portable computing device
ISO-9660 CD format to support PC file systems on CD
media. Supplanted by the Joliet format.
Last Known Good Configuration Option on the
with built-in LCD monitor, keyboard, and trackpad.
laser Single-wavelength, in-phase light source that is sometimes strapped to the head of sharks by bad guys. Note to
henchmen: Lasers should never be used with sea bass, no
matter how ill-tempered they might be.
laser printer Electro-photographic printer in which a laser
is used as the light source.
device, typically used for optical discs.
Advanced Startup Options menu that enables your system to
revert to a previous configuration to troubleshoot and repair
any major system problems.
ISP (Internet service provider) Company that provides
latency Amount of delay before a device may respond to a
ISO file Complete copy (or image) of a storage media
access to the Internet, usually for money.
request; most commonly used in reference to RAM.
jack (physical connection) Part of a connector into which
LBA (logical block addressing) Translation (algorithm) of
a plug is inserted. Also referred to as ports.
Joliet Extension of the ISO 9660 format. Most popular CD
format to support PC file systems on CD media.
joule Unit of energy describing (in this book) how much
energy a surge suppressor can handle before it fails.
joystick Peripheral often used while playing computer
games; originally intended as a multipurpose input device.
Jump List A Windows 7 menu that shows context-sensitive
information about whatever is on the taskbar.
jumper Pair of small pins that can be shorted with a shunt
to configure many aspects of PCs. Often used in configurations that are rarely changed, such as master/slave settings
on IDE drives.
Kerberos Authentication encryption developed by MIT to
enable multiple brands of servers to authenticate multiple
brands of clients.
kernel Core portion of program that resides in memory
and performs the most essential operating system tasks.
IDE drives promoted by Western Digital as a standardized
method for breaking the 504-MB limit in IDE drives. Subsequently universally adopted by the PC industry and now
standard on all EIDE drives.
LCD (liquid crystal display) Type of display commonly
used on portable PCs. Also have mostly replaced CRTs as
the display of choice for most desktop computer users, due
in large part to rapidly falling prices and increasing quality.
LCDs use liquid crystals and electricity to produce images on
the screen.
LED (light-emitting diode) Solid-state device that vibrates
at luminous frequencies when current is applied.
LED monitor LCD monitor that uses LEDs instead of CCFL
tubes for backlighting, creating much higher contrast ratios
and image quality.
Level 1 (L1) cache First RAM cache accessed by the CPU,
which stores only the absolute most-accessed programming
and data used by currently running threads. Always the
smallest and fastest cache on the CPU.
Level 2 (L2) cache Second RAM cache accessed by the
CPU. Much larger and often slower than the L1 cache, and
accessed only if the requested program/data is not in the
L1 cache.
Level 3 (L3) cache Third RAM cache accessed by the
CPU. Much larger and slower than the L1 and L2 caches, and
accessed only if the requested program/data is not in the L2
cache. Seen only on high-end CPUs.
Li-Ion (Lithium-Ion) Battery commonly used in portable
PCs. Li-Ion batteries don’t suffer from the memory effects of
Nickel-Cadmium (Ni-Cd) batteries and provide much more
power for a greater length of time.
Library Feature in Windows 7 that aggregates folders from
multiple locations and places them in a single, easy-to-find
spot in Windows Explorer.
Lightweight Directory Access Protocol (LDAP) Protocol
used by many operating systems and applications to access
limited user account User account in Windows XP that
has limited access to a system. Accounts of this type cannot
alter system files, cannot install new programs, and cannot
edit settings by using the Control Panel.
link light An LED on NICs, hubs, and switches that lights
up to show good connection between the devices.
logon screen First screen of the Windows interface, used to
log on to the computer system.
loopback plug Device used during loopback tests to check
the female connector on a NIC.
Low-Speed USB USB standard that runs at 1.5 Mbps. Also
called USB 1.1.
LPT port Commonly referred to as a printer port; usually
associated with a local parallel port.
LPX First slimline form factor; replaced by NLX form
lumens Unit of measure for amount of brightness on a projector or other light source.
Mac (Also Macintosh.) Apple Computers’ flagship operating system, currently up to OS Xv10.8 “Mountain Lion” and
running on Intel-based hardware.
MAC (media access control) address Unique 48-bit
address assigned to each network card. IEEE assigns blocks
of possible addresses to various NIC manufacturers to help
ensure that the address is always unique. The Data Link layer
of the OSI model uses MAC addresses for locating machines.
MAC address filtering Method of limiting wireless network access based on the physical, hard-wired address of the
units’ wireless NIC.
Linux Open-source UNIX-clone operating system.
machine language Binary instruction code that is under-
liquid cooling A method of cooling a PC that works by
running some liquid—usually water—through a metal block
that sits on top of the CPU, absorbing heat. The liquid gets
heated by the block, runs out of the block and into something
that cools the liquid, and is then pumped through the block
stood by the CPU.
Live DVD The Windows installation media, which loads
matte Laptop screen finish that offers a good balance
the Windows Preinstallation Environment (WinPE) directly
from disc into memory and doesn’t access or modify the
hard drive.
MBR (master boot record) Tiny bit of code that takes con-
Local Security Policy Windows tool used to set local
trol of the boot process from the system BIOS.
­security policies on an individual system.
MCC (memory controller chip) Chip that handles memory requests from the CPU. Although once a special chip, it
has been integrated into the chipset or CPU on modern PCs.
local user account List of user names and their associated
passwords with access to a system, contained in an encrypted
maintenance kits Set of commonly replaced printer components provided by many manufacturers.
mass storage Hard drives, CD-ROMs, removable media
drives, etc.
between richness of colors and reflections, but washes out in
bright light.
MCH (Memory Controller Hub) Intel-coined name for
Local Users and Groups Tool enabling creation and chang-
what is now commonly called the Northbridge.
ing of group memberships and accounts for users.
md (mkdir) command Command in the command-line
log files Files created in Windows to track the progress of
interface used to create directories.
certain processes.
mega- Prefix that stands for the binary quantity 1,048,576
(220) or the decimal quantity of 1,000,000. One megabyte is
1,048,576 bytes. One megahertz, however, is a million hertz.
Sometimes shortened to Meg, as in “a 286 has an address
space of 16 Megs.”
logical drives Sections of an extended partition on a hard
drive that are formatted and (usually) assigned a drive letter,
each of which is presented to the user as if it were a separate
megapixel Term used typically in reference to digital cameras and their ability to capture data.
memory Device or medium for temporary storage of programs and data during program execution. Synonymous
with storage, although it most frequently refers to the internal storage of a computer that can be directly addressed
by operating instructions. A computer’s temporary storage
capacity is measured in kilobytes (KB), megabytes (MB), or
gigabytes (GB) of RAM (random-access memory). Long-term
data storage on disks is also measured in kilobytes, megabytes, gigabytes, and terabytes.
memory addressing Taking memory address from system
RAM and using it to address nonsystem RAM or ROM so the
CPU can access it.
Memory Stick Sony’s flash memory card format; rarely
seen outside of Sony devices.
mesh topology Network topology where each computer
has a dedicated line to every other computer, most often used
in wireless networks.
MFT (master file table) Enhanced file allocation table
used by NTFS. (See also FAT.)
microATX (μATX) Variation of the ATX form factor,
which uses the ATX power supply. MicroATX motherboards
are generally smaller than their ATX counterparts but retain
all the same functionality.
migration Moving users from one operating system or
hard drive to another.
MIMO (multiple in/multiple out) Feature of 802.11n
devices that enables the simultaneous connection of up to
four antennas, greatly increasing throughput.
mini-audio connector Very popular, 1/8-inch diameter
connector used to transmit two audio signals; perfect for
­stereo sound.
mini connector One type of power connector from a PC
power supply unit. Supplies 5 and 12 volts to peripherals.
Also known as a floppy connector.
mini-DIN Small connection most commonly used for keyboards and mice. Many modern systems implement USB in
place of mini-DIN connections. Also called PS/2.
Mini-ITX The largest and the most popular of the three
ITX form factors. At a miniscule 6.7 by 6.7 inches, Mini-ITX
competes with microATX and proprietary small form factor
(SFF) motherboards.
Mini-PCI Specialized form of PCI designed for use in
Mini-PCIe Specialized form of PCIe designed for use in
mini power connector Connector used to provide power
to floppy disk drives.
microBTX Variation of the BTX form factor. MicroBTX
motherboards are generally smaller than their BTX counterparts but retain all the same functionality.
mirror set A type of mirrored volume created by Windows
7 Professional, Enterprise, and Ultimate editions. (See also
microdrive Tiny hard drives using the CompactFlash form
factor. (See also CompactFlash (CF).)
mirrored volume Volume that is mirrored on another volume. (See also mirroring.)
microprocessor “Brain” of a computer. Primary computer
chip that determines relative speed and capabilities of the
computer. Also called CPU.
mirroring Reading and writing data at the same time to
two drives for fault tolerance purposes. Considered RAID
level 1. Also called drive mirroring.
Microsoft Certified IT Professional (MCITP) An
MMC (Microsoft Management Console) Means of man-
advanced IT certification specifically covering Microsoft
MIDI (musical instrument digital interface) Interface
between a computer and a device for simulating musical
instruments. Rather than sending large sound samples, a
computer can simply send “instructions” to the instrument
describing pitch, tone, and duration of a sound. MIDI files
are therefore very efficient. Because a MIDI file is made up of
a set of instructions rather than a copy of the sound, modifying each component of the file is easy. Additionally, it is possible to program many channels, or “voices,” of music to be
played simultaneously, creating symphonic sound.
MIDI-enabled device External device that enables you
to input digital sound information in the MIDI format; for
example, a MIDI keyboard (the piano kind).
aging a system, introduced by Microsoft with Windows 2000.
The MMC allows an administrator to customize management
tools by picking and choosing from a list of snap-ins. Available snap-ins include Device Manager, Users and Groups,
and Computer Management.
MMX (multimedia extensions) Specific CPU instructions
that enable a CPU to handle many multimedia functions,
such as digital signal processing. Introduced with the Pentium CPU, these instructions are used on all ×86 CPUs.
mode Any single combination of resolution and color
depth set for a system.
modem (modulator/demodulator) Device that converts
a digital bit stream into an analog signal (modulation) and
converts incoming analog signals back into digital signals
(demodulation). Analog communications channel is typically
a telephone line, and analog signals are typically sounds.
module Small circuit board that DRAM chips are attached
to. Also known as a “stick.”
Molex connector Computer power connector used by
optical drives, hard drives, and case fans. Keyed to prevent it
from being inserted into a power port improperly.
monaural Describes recording tracks from one source
(microphone) as opposed to stereo, which uses two sources.
enables users to configure a system’s boot files and critical
system files. Often used for the name of the utility, as in “just
run msconfig.”
MSDS (material safety data sheet) Standardized form
that provides detailed information about potential environmental hazards and proper disposal methods associated with
various PC components.
msinfo32 Provides information about hardware resources,
components, and the software environment. Also known as
System Information.
monitor Screen that displays data from a PC. Can use
either a cathode ray tube (CRT) or a liquid crystal display
(LCD) to display images.
multiboot installation OS installation in which multiple
motherboard Flat piece of circuit board that resides inside
multicore processing Using two or more execution cores
on one CPU die to divide up work independently of the OS.
your computer case and has a number of connectors on it.
Every device in a PC connects directly or indirectly to the
motherboard, including CPU, RAM, hard drives, optical
drives, keyboard, mouse, and video cards.
motherboard book Valuable resource when installing a
new motherboard. Normally lists all the specifications about
a motherboard, including the type of memory and type of
CPU usable with the motherboard.
mount point Drive that functions like a folder mounted
into another drive.
mouse Input device that enables users to manipulate a cursor on the screen to select items.
move command Command in the command-line interface
used to move a file from one location to another.
MP3 Short for MPEG Audio Layer 3. A type of compression used specifically for turning high-quality digital audio
files into much smaller, yet similar sounding, files.
MPA (Microsoft Product Activation) Introduced by
Microsoft with the release of Windows XP, prevents unauthorized use of Microsoft’s software by requiring users to
activate the software.
MPEG-2 (Moving Pictures Experts Group) Standard of
video and audio compression offering resolutions up to 1280
× 720 at 60 frames per second.
MPEG-4 (Moving Pictures Experts Group) Standard of
video and audio compression offering improved compression over MPEG-2.
MS-CHAP Microsoft’s variation of the CHAP protocol,
which uses a slightly more advanced encryption protocol.
Windows Vista uses MS-CHAP v2 (version 2), and does not
support MS-CHAP v1 (version 1).
msconfig (System Configuration Utility) Executable file
that runs the Windows System Configuration utility, which
operating systems are installed on a single machine. Can also
refer to kicking a device several times in frustration.
multimedia extensions (MMX) Originally an Intel CPU
enhancement designed for graphics-intensive applications
(such as games). It was never embraced but eventually led to
improvements in how CPUs handle graphics.
multimeter Device used to measure voltage, amperage,
and resistance.
multisession drive Recordable CD drive capable of burning multiple sessions onto a single recordable disc. A multisession drive also can close a CD-R so that no further tracks
can be written to it.
multitasking Process of running multiple programs or
tasks on the same computer at the same time.
multitouch Input method on many smartphones and tablets that enables you to use multiple fingers to do all sorts
of fun things, such as using two fingers to scroll or swipe to
another screen or desktop.
music CD-R CD using a special format for home recorders. Music CD-R makers pay a small royalty to avoid illegal
music duplication.
My Computer Default interface in Windows XP for
Windows Explorer; displays hard drives and devices with
removeable storage. (See Computer.).
My Documents Introduced with Windows 98 and used in
Windows 2000 and Windows XP; folder that provides a convenient place for users to store their documents, log files, and
any other type of files.
My Network Places Folder in Windows XP that
enables users to view other computers on their network or
Nano-ITX A 4.7 inch by 4.7 inch variation of the ITX
form factor.
NAT (Network Address Translation) A means of translating a system’s IP address into another IP address before
sending it out to a larger network. NAT manifests itself by a
NAT program that runs on a system or a router. A network
using NAT provides the systems on the network with private
IP addresses. The system running the NAT software has two
interfaces: one connected to the network and the other connected to the larger network.
The NAT program takes packets from the client systems
bound for the larger network and translates their internal private IP addresses to its own public IP address, enabling many
systems to share a single IP address.
native resolution Resolution on an LCD monitor that
matches the physical pixels on the screen. CRTs do not have
fixed pixels and therefore do not have a native resolution.
navigation pane Windows 7’s name for the Folders list in
Windows Explorer.
net command Command in Windows that enables users
to view a network without knowing the names of the other
computers on that network.
NetBIOS (Network Basic Input/Output System) Protocol that operates at the Session layer of the OSI seven-layer
model. This protocol creates and manages connections based
on the names of the computers involved.
NetBIOS Extended User Interface (NetBEUI) The
default networking protocol for early versions of Windows.
netbook Small, low-power laptop used primarily for Web
network Collection of two or more computers interconnected by telephone lines, coaxial cables, satellite links, radio,
and/or some other communication technique. Group of computers that are connected and that communicate with one
another for a common purpose.
Network Interface in Windows Vista and Windows 7 for
Windows Explorer; displays networked computers and other
devices, such as network printers.
network attached storage (NAS) A device that attaches
to a network for the sole purpose of storing and sharing files.
network ID Number that identifies the network on which
a device or machine exists. This number exists in both IP and
IPX protocol suites.
network printer Printer that connects directly to a
network protocol Software that takes the incoming data
received by the network card, keeps it organized, sends it to
the application that needs it, and then takes outgoing data
from the application and hands it to the NIC to be sent out
over the network.
network technology A practical application of a topology
and other critical standards to provide a method to get data
from one computer to another on a network. It defines many
aspects of a network, from the topology, to the frame type, to
the cabling and connectors used.
NIC (network interface card or controller) Expansion
card or motherboard interface that enables a PC to connect to
a network via a network cable. A wireless NIC enables connection via radio waves rather than a physical cable.
Ni-Cd (Nickel-Cadmium) Battery used in the first portable PCs. Heavy and inefficient, these batteries also suffered
from a memory effect that could drastically shorten the overall life of the battery. (See also Ni-MH, Li-Ion.)
Ni-MH (Nickel-Metal Hydride) Battery used in early portable PCs. Ni-MH batteries had fewer issues with the memory effect than Ni-Cd batteries. Ni-MH batteries have been
replaced by Lithium-Ion batteries. (See also Ni-Cd, Li-Ion.)
nit Value used to measure the brightness of an LCD display. A typical LCD display has a brightness of between 100
and 400 nits.
NLQ (near-letter quality) Designation for dot-matrix
printers that use 24-pin printheads.
NLX Second form factor for slimline systems. Replaced the
earlier LPX form factor. (NLX apparently stands for nothing;
it’s just a cool grouping of letters.)
NMI (non-maskable interrupt) Interrupt code sent to the
processor that cannot be ignored. Typically manifested as a
NNTP (Network News Transfer Protocol) Protocol run
by news servers that enable newsgroups.
non-system disk or disk error Error that occurs during
the boot process. Common causes for this error are leaving
a nonbootable floppy disk, CD, or other media in the drive
while the computer is booting.
nonvolatile memory Storage device that retains data even
if power is removed; typically refers to a ROM or flash ROM
chip, but also could be applied to hard drives, optical media,
and other storage devices.
normal backup Full backup of every selected file on a system. Turns off the archive bit after the backup.
Northbridge Chip that connects a CPU to memory, the PCI
bus, Level 2 cache, and AGP activities. Communicates with
the CPU through the frontside bus. Newer CPUs feature an
integrated Northbridge.
notebook See laptop.
notification area Contains icons representing background
processes, the system clock, and volume control. Located by
default at the right edge of the Windows taskbar. Most users
call this area the system tray.
optical disc/media Types of data discs (such as DVDs,
CDs, BDs, etc.) that are read by a laser.
nslookup Command-line program in Windows used to
optical drive Drive used to read/write to optical discs,
determine exactly what information the DNS server is providing about a specific host name.
such as CDs or DVDs. One of the critical Windows NT/2000/XP
startup files.
optical mouse Pointing device that uses light rather than
electronic sensors to determine movement and direction the
mouse is being moved.
NTFS (NT file system) Robust and secure file system
introduced by Microsoft with Windows NT. NTFS provides
an amazing array of configuration options for user access
and security. Users can be granted access to data on a file-byfile basis. NTFS enables object-level security, long filename
support, compression, and encryption.
optical resolution Resolution a scanner can achieve
mechanically. Most scanners use software to enhance this
NTFS permissions Restrictions that determine the amount
option ROM Alternative way of telling the system how to
of access given to a particular user on a system using NTFS.
ntldr (NT Loader) Windows NT/2000/XP boot file.
Launched by the MBR or MFT, ntldr looks at the boot.ini configuration file for any installed operating systems.
NVIDIA Corporation One of the foremost manufacturers
of graphics cards and chipsets.
object System component that is given a set of characteristics and can be managed by the operating system as a single
object access auditing Feature of Event Viewer’s Security
section that creates an entry in the Security Log when certain
objects are accessed, such as a file or folder.
ODBC Data Source Administrator Programming tool for
configuring the Open Database Connectivity (ODBC) coding
standard. Data Source Administrator enables you to create
and manage entries called Data Source Names (DSNs) that
point OBDC to a database. DSNs are used by ODBC-aware
applications to query ODBC to find their databases.
offline files Windows 7 feature that enables storing a local,
duplicate copy of files and folders on a hard drive. When the
laptop connects to a network, Windows automatically syncs
those offline files with the files and folders on a file server or
other PC.
ohm(s) Electronic measurement of a cable’s impedance.
open source Software environment that is not controlled
by a central creator or distributer.
OLED (organic light-emitting diode) Display technology
where an organic compound provides the light for the screen,
thus eliminating the need for a backlight or inverter.
OpenGL One of two popular APIs used today for video
cards. Originally written for UNIX systems but now ported
to Windows and Apple systems. (See also DirectX.)
optical zoom Mechanical ability of most cameras to
“zoom” in as opposed to the digital ability.
talk to a piece of hardware. Option ROM stores BIOS for the
card in a chip on the card itself.
OS (operating system) Series of programs and code that
creates an interface so users can interact with a system’s
hardware; for example, DOS, Windows, and Linux.
OS X Current operating system on Apple Macintosh computers. Based on a UNIX core, early versions of OS X ran
on Motorola-based hardware; current versions run on Intelbased hardware. Pronounced “ten” rather than “ex.”
OSI seven-layer model Architecture model based on the
OSI protocol suite that defines and standardizes the flow of
data between computers. The seven layers are:
ayer 1 The Physical layer Defines hardware conL
nections and turns binary into physical pulses (electrical or light). Repeaters and hubs operate at the Physical layer.
ayer 2 The Data Link layer Identifies devices on
the Physical layer. MAC addresses are part of the Data
Link layer. Bridges operate at the Data Link layer.
ayer 3 The Network layer Moves packets between
computers on different networks. Routers operate at
the Network layer. IP and IPX operate at the Network
ayer 4 The Transport layer Breaks data down into
manageable chunks. TCP, UDP, SPX, and NetBEUI
operate at the Transport layer.
ayer 5 The Session layer Manages connections
between machines. NetBIOS and Sockets operate at the
Session layer.
ayer 6 The Presentation layer Can also manage
data encryption; hides the differences between various
types of computer systems.
ayer 7 The Application layer Provides tools for
programs to use to access the network (and the lower
layers). HTTP, FTP, SMTP, and POP3 are all examples
of protocols that operate at the Application layer.
overclocking To run a CPU or video processor faster than
passcode lock Mobile device security feature that requires
its rated speed.
you to type in a series of letters, numbers, or motion patterns
to unlock the mobile device each time you press the power
P1 power connector Provides power to ATX motherboards; 20-pin with original ATX motherboards, 24-pin on
current units.
P4 12V connector Provides additional 12-volt power to
motherboards that support Pentium 4 and later processors.
P8 and P9 connectors Provide power to AT-style
packet Basic component of communication over a network. Group of bits of fixed maximum size and well-defined
format that is switched and transmitted as a single entity
through a network. Contains source and destination address,
data, and control information.
page fault Minor memory-addressing error.
page file Portion of the hard drive set aside by Windows to
act like RAM. Also known as virtual memory or swap file.
PAN (personal area network) Small wireless network created with Bluetooth technology and intended to link PCs and
other peripheral devices.
parallel execution When a multicore CPU processes more
than one thread.
parallel port Connection for the synchronous, high-speed
flow of data along parallel lines to a device, usually a printer.
Parental Controls Tool to allow monitoring and limiting
of user activities; designed for parents to control the content
their children can access.
parity Method of error detection where a small group of
bits being transferred is compared to a single parity bit set to
make the total bits odd or even. Receiving device reads the
parity bit and determines if the data is valid, based on the
oddness or evenness of the parity bit.
parity RAM Earliest form of error-detecting RAM; stored
an extra bit (called the parity bit) to verify the data.
partition Section of the storage area of a hard disk. Created
during initial preparation of the hard disk, before the disk is
partition boot table Sector of a partition that stores information important to its partition, such as the location of the
OS boot files. Responsible for loading the OS on a partition.
partition table Table located in the boot sector of a hard
drive that lists every partition on the disk that contains a
valid operating system.
partitioning Electronically subdividing a physical hard
drive into groups called partitions (or volumes).
passive matrix Technology for producing colors in LCD
monitors by varying voltages across wire matrices to produce
red, green, or blue dots.
password Key used to verify a user’s identity on a secure
computer or network.
Password Authentication Protocol (PAP) Oldest and
most basic form of authentication. Also the least safe, because
it sends all passwords in clear text.
password reset disk Special type of floppy disk with
which users can recover a lost password without losing
access to any encrypted, or password-protected, data.
PATA (parallel ATA) Implementation that integrates the
controller on the disk drive itself. (See also ATA, IDE, SATA.)
patch Small piece of software released by a software manufacturer to correct a flaw or problem with a particular piece
of software.
patch cables Short (2 to 5 feet) UTP cables that connect
patch panels to the hubs.
patch panel A panel containing a row of female connectors
(ports) that terminate the horizontal cabling in the equipment
room. Patch panels facilitate cabling organization and provide protection to horizontal cabling.
path Route the operating system must follow to find an
executable program stored in a subfolder.
PC bus Original 8-bit expansion bus developed by IBM
for PCs; ran at a top speed of 4.77 MHz. Also known as the
XT bus.
PC Card Credit card–sized adapter card that adds functionality in many notebook computers, PDAs, and other computer devices. PC Cards come in 16-bit and CardBus parallel
format and ExpressCard serial format. (See also PCMCIA.)
PC tech Someone with computer skills who works on
PCI (Peripheral Component Interconnect) Design
architecture for the expansion bus on the computer motherboard that enables system components to be added to the
computer. Local bus standard, meaning that devices added
to a computer through this port will use the processor at the
motherboard’s full speed (up to 33 MHz) rather than at the
slower 8-MHz speed of the regular bus. Moves data 32 or 64
bits at a time rather than the 8 or 16 bits the older ISA buses
PCIe (PCI Express) Serialized successor to PCI and AGP
that uses the concept of individual data paths called lanes.
May use any number of lanes, although a single lane (×1) and
16 lanes (×16) are the most common on motherboards.
Performance Options Tool enabling users to configure
PCI-X (PCI Extended) Enhanced version of PCI, 64 bits
peripheral Any device that connects to the system unit.
wide. Typically seen in servers and high-end systems.
PCL (printer control language) Printer control language
created by Hewlett-Packard and used on a broad cross-section of printers.
PCM (pulse code modulation) Sound format developed
in the 1960s to carry telephone calls over the first digital lines.
PCMCIA (Personal Computer Memory Card International
Association) Consortium of computer manufacturers who
devised the PC Card standard for credit card–sized adapter
cards that add functionality in many notebook computers,
PDAs, and other computer devices. (See also PC Card.)
PDA (personal digital assistant) Handheld computer that
blurred the line between calculators and computers. Early
PDAs were calculators that enabled users to program in such
information as addresses and appointments. Later PDAs,
such as the Palm and PocketPC, were fully programmable
computers. Most PDAs used a pen/stylus for input rather
than a keyboard. A few of the larger PDAs had a tiny keyboard in addition to the stylus. Smartphones and tablets have
supplanted PDAs for almost all uses.
Pearson VUE The company that administers the CompTIA
CPU, RAM, and virtual memory settings.
permission propagation Term to describe what happens
to permissions on an object when you move or copy it.
persistence Phosphors used in CRT screens continuing
to glow after being struck by electrons, long enough for the
human eye to register the glowing effect. Glowing too long
makes the images smeary, and too little makes them flicker.
Personalization applet Windows Vista applet with which
users can change display settings such as resolution, refresh
rate, color depth, and desktop features. The Windows 7 version focuses on managing themes, desktop icons, mouse
pointers, and account pictures. For other options, see Display.
PGA (pin grid array) Arrangement of a large number of
pins extending from the bottom of the CPU package. There
are many variations on PGA.
Phillips-head screwdriver Most important part of a PC
tech’s toolkit.
phishing The act of trying to get people to give their usernames, passwords, or other security information by pretending to be someone else electronically.
Phoenix Technologies Major producer of BIOS software
A+ exams.
for motherboards.
peer-to-peer network Network in which each machine
can act as both a client and a server.
phosphor Electro-fluorescent material that coats the inside
face of a cathode ray tube (CRT). After being hit with an electron, it glows for a fraction of a second.
pen-based computing Input method used by many PDAs
that combines handwriting recognition with modified mouse
functions, usually in the form of a pen-like stylus.
Pentium Name given to the fifth and later generations of
photosensitive drum Aluminum cylinder coated with
particles of photosensitive compounds. Used in a laser
printer and often contained within the toner cartridge.
Intel microprocessors; has a 32-bit address bus, 64-bit external data bus, and dual pipelining. Also used for subsequent
generations of Intel processors—the Pentium Pro, Pentium II,
Pentium III, and Pentium 4. Pentium name was retired after
the introduction of the Intel Core CPUs.
picoBTX Variation of the BTX form factor. picoBTX moth-
Performance Tab in Task Manager that tracks PC
pin 1 Designator used to ensure proper alignment of
floppy drive and hard drive connectors.
Performance console Windows XP tool used to log
resource usage over time.
erboards are generally smaller than their BTX or microBTX
counterparts but retain the same functionality.
Pico-ITX A 3.8 by 2.8 inch version of the ITX form factor.
pinch Multitouch gesture that enables you to make an
image bigger or smaller.
Performance Information and Tools Applet that provides
a relative feel for how your computer stacks up against other
systems using the Windows Experience Index.
pinned application Windows 7’s method of attaching pro-
Performance Logs and Alerts Snap-in enabling the cre-
ping (packet Internet groper) Slang term for a small net-
ation of a written record of most everything that happens on
the system.
Performance Monitor Windows 7’s tool for observing a
computer’s performance.
grams to the taskbar. A pinned application gets a permanent
icon displayed on the taskbar.
work message (ICMP ECHO) sent by a computer to check
for the presence and aliveness of another. Used to verify the
presence of another system. Also, the command used at a
prompt to ping a computer.
PIO (programmed I/O) mode Series of speed standards
created by the Small Form Factor Committee for the use of
PIO by hard drives. Modes range from PIO mode 0 to PIO
mode 4.
port triggering Router function that enables you to automatically open an incoming connection to one computer
based on a specific outgoing connection.
positional audio Range of commands for a sound card to
pipeline Processing methodology where multiple calcula-
place a sound anywhere in 3-D space.
tions take place simultaneously by being broken into a series
of steps. Often used in CPUs and video processors.
POST (power-on self test) Basic diagnostic routine com-
pixel (picture element) In computer graphics, smallest element of a display space that can be independently
assigned color or intensity.
plug Hardware connection with some sort of projection
that connects to a port.
plug and play (PnP) Combination of smart PCs, smart
devices, and smart operating systems that automatically
configure all necessary system resources and ports when you
install a new peripheral device.
polygons Multisided shapes used in 3-D rendering of
objects. In computers, video cards draw large numbers of
triangles and connect them to form polygons.
polymorph virus Virus that attempts to change its signature to prevent detection by antivirus programs, usually by
continually scrambling a bit of useless code.
polyphony Number of instruments a sound card can play
POP3 (Post Office Protocol) Refers to the way e-mail
software such as Eudora gets mail from a mail server. When
you obtain a SLIP, PPP, or shell account, you almost always
get a POP account with it. It is this POP account that you tell
your e-mail software to use to get your mail. Uses port 110.
pop-up Irritating browser window that appears automatically when you visit a Web site.
port (networking) In networking, the number used to
identify the requested service (such as SMTP or FTP) when
connecting to a TCP/IP host. Examples: 80 (HTTP), 20 (FTP),
69 (TFTP), 25 (SMTP), and 110 (POP3).
port (physical connection) Part of a connector into which
a plug is inserted. Physical ports are also referred to as jacks.
port forwarding Preventing the passage of any IP packets
through any ports other than the ones prescribed by the system administrator.
port replicator Device that plugs into a USB port or other
specialized port and offers common PC ports, such as serial,
parallel, USB, network, and PS/2. By plugging your notebook computer into the port replicator, you can instantly
connect the computer to non-portable components such as a
printer, scanner, monitor, or full-sized keyboard. Port replicators are typically used at home or in the office with the nonportable equipment already connected.
pleted by a system at the beginning of the boot process to
make sure a display adapter and the system’s memory are
installed; it then searches for an operating system. If it finds
one, it hands over control of the machine to the OS.
PostScript Language defined by Adobe Systems, Inc. for
describing how to create an image on a page. The description
is independent of the resolution of the device that will actually create the image. It includes a technology for defining
the shape of a font and creating a raster image at many different resolutions and sizes.
power conditioning Ensuring and adjusting incoming
AC wall power to as close to standard as possible. Most UPS
devices provide power conditioning.
power good wire Used to wake up the CPU after the
power supply has tested for proper voltage.
Power over Ethernet Technology that provides power and
data transmission through a single network cable.
power plans Windows Vista/7 feature that enables better
control over power use by customizing a balanced, power
saver, or high performance power plan.
PowerShell See Windows PowerShell.
power supply fan Small fan located in a system power
supply that draws warm air from inside the power supply
and exhausts it to the outside.
power supply unit Provides the electrical power for a PC.
Converts standard AC power into various voltages of DC
electricity in a PC.
Power Users group Second most powerful account and
group type in Windows after Administrators.
ppm (pages per minute) Speed of a printer.
PPP (Point-to-Point Protocol) Enables a computer to connect to the Internet through a dial-in connection and enjoy
most of the benefits of a direct connection.
preboot execution environment (PXE) Technology that
enables a PC to boot without any local storage by retrieving
an OS from a server over a network.
primary corona Wire that is located near the photosensitive drum in a laser printer and is charged with extremely
high voltage to form an electric field, enabling voltage to pass
to the photosensitive drum, thus charging the photosensitive
particles on the surface of the drum. Also called the primary
charge roller.
primary partition Partition on a Windows hard drive that
can store a bootable operating system.
print resolution Quality of a print image.
print spooler Area of memory that queues up print jobs
that the printer will handle sequentially.
printed circuit board (PCB) Copper etched onto a nonconductive material and then coated with some sort of epoxy for
printer Output device that can print text or illustrations on
paper. Microsoft uses the term to refer to the software that
controls the physical print device.
printhead Case that holds the printwires in a dot-matrix
printwires Grid of tiny pins in a dot-matrix printer that
strike an inked printer ribbon to produce images on paper.
PRML (Partial Response Maximum Likelihood) Advanced method of RLL that uses powerful, intelligent
circuitry to analyze each flux reversal on a hard drive and to
make a best guess as to what type of flux reversal it just read.
This allows a dramatic increase in the amount of data a hard
drive can store.
Problem Reports and Solutions Control Panel applet in
Windows Vista that lists all Windows Error Reporting issues
(plus a few easy-to-check items like firewall and antimalware
Processes Tab in Task Manager that lists all running pro-
protocol Agreement that governs the procedures used to
exchange information between cooperating entities. Usually
includes how much information is to be sent, how often it is
sent, how to recover from transmission errors, and who is to
receive the information.
proxy server Device that fetches Internet resources for a
client without exposing that client directly to the Internet.
Usually accepts requests for HTTP, FTP, POP3, and SMTP
resources. Often caches, or stores, a copy of the requested
resource for later use. Common security feature in the corporate world.
Public folder Folder that all users can access and share
with all other users on the system or network.
punchdown tool A specialized tool for connecting UTP
wires to an punchdown block.
Quality of Service (QoS) Policies that control how
much bandwidth a protocol, PC, user, VLAN, or IP address
may use.
queue Area where objects wait their turn to be processed.
Example: the printer queue, where print jobs wait until it is
their turn to be printed.
Quick Launch toolbar Enables you to launch commonly
used programs with a single click.
QVGA Video display mode of 320 × 240.
RAID (redundant array of independent disks) Sevenlevel (0–6) way of creating a fault-tolerant storage system:
Level 0 Uses byte-level striping and provides no fault
cesses on a system. Frequently a handy tool for ending buggy
or unresponsive processes.
Level 1 Uses mirroring or duplexing.
product key Code used during installation to verify legiti-
evel 3 Stores error-correcting information (such as
parity) on a separate disk, and uses data striping on the
remaining drives.
macy of the software.
profile A list of settings that a calibration device creates
when calibrating monitors and printers.
program/programming Series of binary electronic commands sent to a CPU to get work done.
Programs and Features Windows Vista/7 replacement for
the Add or Remove Programs applet; enables uninstalling
programs and altering Windows features.
Level 2 Uses bit-level striping.
Level 4 Level 3 with block-level striping.
Level 5 Uses block-level and parity data striping.
evel 6 Same as RAID 5 but with double distributed
Also known as redundant array of inexpensive disks.
RAID 5 volume Striped set with parity. (See also RAID).
projector Device for projecting video images from PCs
rails Separate DC voltage paths within an ATX power
or other video sources, usually for audience presentations.
Available in front- and rearview displays.
prompt A character or message provided by an operating
system or program to indicate that it is ready to accept input.
proprietary Technology unique to a particular vendor.
RAM (random access memory) Memory that can be
accessed at random; that is, memory which you can write to
or read from without touching the preceding address. This
term is often used to mean a computer’s main memory.
RAMDAC (random access memory digital-to-analog converter) Circuitry used on video cards that support analog
monitors to convert the digital video data to analog.
raster image Pattern of dots representing what the final
product should look like.
Remote Desktop Windows tool used to enable a local system to graphically access the desktop of a remote system.
Remote Desktop Protocol Protocol used for Microsoft’s
Remote Desktop tool. Uses port 3389.
remote network installation A common method of OS
RDRAM (Rambus DRAM) Patented RAM technology that
uses accelerated clocks to provide very high-speed memory.
installation where the source files are placed in a shared
directory on a network server. Then, whenever a tech needs
to install a new OS, he can boot the computer, connect to
the source location on the network, and start the installation
from there.
read-only attribute File attribute that does not allow a file
to be altered or modified. Helpful when protecting system
files that should not be edited.
removable media Any storage on a computer that can be
easily removed. For example, CD-ROM discs, flash drives, or
memory cards.
rd (rmdir) command Command in the command-line
interface used to remove directories.
ren (rename) command Command in the command-line
interface used to rename files and folders.
rearview projector Projector that shoots an image onto
resistance Difficulty in making electricity flow through a
material, measured in ohms.
raster line Horizontal pattern of lines that forms an image
on the monitor screen.
a screen from the rear. Rearview projectors are usually selfenclosed and very popular for TVs, but are virtually unheard
of in the PC world.
Recovery Console Command-line interface boot mode for
Windows that is used to repair a Windows XP system suffering from massive OS corruption or other problems.
Recycle Bin Location to which files are moved when they
are deleted from a modern Windows system. To permanently
remove files from a system, they must be emptied from the
Recycle Bin.
regedit.exe Program used to edit the Windows Registry.
region code Encoding that restricts you from playing DVD
or Blu-ray Disc movies on a player that doesn’t share the
same region code.
register Storage area inside the CPU used by the onboard
logic to perform calculations. CPUs have many registers to
perform different functions.
registration Usually optional process that identifies the
legal owner/user of the product to the supplier.
Registry Complex binary file used to store configuration
data about a particular system. To edit the Registry, users can
use the applets found in the Control Panel or regedit.exe or
Reliability and Performance Monitor Windows Vista’s
extended Performance applet.
remediation Repairing damage caused by a virus.
remnant Potentially recoverable data on a hard drive that
resistive touchscreen Type of touchscreen that responds
to the pressure applied to the screen.
resistor Any material or device that impedes the flow
of electrons. Electronic resistors measure their resistance
(impedance) in ohms. (See ohm(s).)
resolution Measurement for CRTs and printers expressed
in horizontal and vertical dots or pixels. Higher resolutions
provide sharper details and thus display better-looking
resources Data and services of a PC.
respect How all techs should treat their customers.
response rate Time it takes for all of the sub-pixels on the
panel to go from pure black to pure white and back again.
restore point System snapshot created by the System
Restore utility that is used to restore a malfunctioning system. (See also System Restore.)
RET (resolution enhancement technology) Technology that uses small dots to smooth out jagged edges that are
typical of printers without RET, producing a higher-quality
print job.
RFI (radio frequency interference) Another form of electrical interference caused by radio-wave emitting devices,
such as cell phones, wireless network cards, and microwave
RG-58 Coaxial cabling used for 10Base2 networks.
remains despite formatting or deleting.
RIMM Individual stick of Rambus RAM. The letters don’t
Remote Assistance Feature of Windows that enables users
actually stand for anything; they just rhyme with SIMM and
to give anyone control of his or her desktop over the Internet.
ring Network topology where the computers form a circle
and all data flows in one direction only.
RIP (raster image processor) Component in a printer that
translates the raster image into commands for the printer.
riser card Special adapter card, usually inserted into a
special slot on a motherboard, that changes the orientation of
expansion cards relative to the motherboard. Riser cards are
used extensively in slimline computers to keep total depth
and height of the system to a minimum. Sometimes called a
RJ (registered jack) connector UTP cable connector, used
for both telephone and network connections. RJ-11 is a connector for four-wire UTP; usually found in telephone connections. RJ-45 is a connector for eight-wire UTP; usually found
in network connections.
RJ-11 See RJ (registered jack) connector.
RJ-45 See RJ (registered jack) connector.
robocopy command Powerful command-line utility for
copying files and directories, even over a network.
ROM (read-only memory) Generic term for nonvolatile
memory that can be read from but not written to. This means
that code and data stored in ROM cannot be corrupted by
accidental erasure. Additionally, ROM retains its data when
power is removed, which makes it the perfect medium for
storing BIOS data or information such as scientific constants.
root directory Directory that contains all other directories.
root keys Five main categories in the Windows Registry:
router Device connecting separate networks; forwards a
packet from one network to another based on the network
address for the protocol being used. For example, an IP
router looks only at the IP network number. Routers operate
at Layer 3 (Network) of the OSI seven-layer model.
RS-232 Standard port recommended by the Electronics
Industry Association for serial devices.
run A single piece of installed horizontal cabling.
Run dialog box Command box in which users can enter
the name of a particular program to run; an alternative to
locating the icon in Windows.
S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting
Technology) Monitoring system built into hard drives.
S/PDIF (Sony/Philips Digital Interface Format) Digital
audio connector found on many sound cards. Users can
connect their computers directly to a 5.1 speaker system
or receiver. S/PDIF comes in both a coaxial and an optical
Safe Mode Important diagnostic boot mode for Windows that only runs very basic drivers and turns off virtual
sampling Capturing sound waves in electronic format.
SATA (serial ATA) Serialized version of the ATA standard that offers many advantages over PATA (parallel ATA)
technology, including thinner cabling, keyed connectors, and
lower power requirements.
SATA bridge Adapter that allows PATA devices to be connected to a SATA controller.
SATA power connector 15-pin, L-shaped connector used
by SATA devices that support the hot-swappable feature.
satellites Two or more standard stereo speakers to be combined with a subwoofer for a speaker system (i.e., 2.1, 5.1,
Scalable Link Interface (SLI) Technology for connecting
two or more NVIDIA GPUs together in a system.
scan code Unique code corresponding to each key on the
keyboard, sent from the keyboard controller to the CPU.
Scheduled Tasks Windows XP’s utility enabling users to
set tasks to run automatically at certain times.
SCSI (small computer system interface) Powerful and
flexible peripheral interface popularized on the Macintosh
and used to connect hard drives, CD-ROM drives, tape
drives, scanners, and other devices to PCs of all kinds.
Normal SCSI enables up to seven devices to be connected
through a single bus connection, whereas Wide SCSI can
handle 15 devices attached to a single controller.
SCSI chain Series of SCSI devices working together
through a host adapter.
SCSI ID Unique identifier used by SCSI devices. No two
SCSI devices may have the same SCSI ID.
SD (Secure Digital) Very popular format for flash media
cards; also supports I/O devices.
SDRAM (synchronous DRAM) DRAM that is synchronous, or tied to the system clock and thus runs much faster
than traditional FPM and EDO RAM. This type of RAM is
used in all modern systems.
SEC (single-edge cartridge) CPU package where the CPU
was contained in a cartridge that snapped into a special slot
on the motherboard called Slot 1.
sector Segment of one of the concentric tracks encoded on
the disk during a low-level format. A sector holds 512 bytes
of data.
sector translation Translation of logical geometry into
physical geometry by the onboard circuitry of a hard drive.
SID (security identifier) Unique identifier for every PC
that most techs change when cloning.
sectors per track (sectors/track) Combined with the
sidebanding Second data bus for AGP video cards; enables
number of cylinders and heads, defines the disk geometry.
the video card to send more commands to the Northbridge
while receiving other commands at the same time.
segment The connection between a computer and a switch.
serial port Common connector on a PC. Connects input
devices (such as a mouse) or communications devices (such
as a modem).
server Computer that shares its resources, such as printers and files, with other computers on a network. Example:
network file system server that shares its disk space with a
workstation that does not have a disk drive of its own.
service A program that runs in the background of a PC but
signal-to-noise ratio Measure that describes the relative
quality of an input port.
signature Code pattern of a known virus; used by antivirus software to detect viruses.
SIMM (single in-line memory module) DRAM packaging
distinguished by having a number of small tabs that install
into a special connector. Each side of each tab is the same signal. SIMMs come in two common sizes: 30-pin and 72-pin.
displays no icons anywhere. You can view a list of services
in the Task Manager Windows Vista and Windows 7. Also,
a program stored in a ROM chip.
simple file sharing Allows users to share locally or across
service pack Collection of software patches released at one
time by a software manufacturer.
simple volume Volume created when setting up dynamic
disks. Acts like a primary partition on a dynamic disk.
Services Tab in Windows Vista/7’s Task Manager that lists
all running services on a system.
single-sided RAM Has chips on only one side as opposed
to double-sided RAM.
setupapi.log Log file that tracks the installation of all hard-
single source See closed source.
ware on a system.
setuplog.txt Log file that tracks the complete installation
process, logging the success or failure of file copying, Registry updates, and reboots.
the network but gives no control over what others do with
shared files.
sleep timers A feature that enables you to put the computer into Standby after a set period of time, or to turn off the
monitor or hard drive after a time, thus creating your own
custom power scheme.
sfc (System File Checker) Command-prompt program
(sfc.exe) that scans, detects, and restores Windows system
files, folders, and paths.
slimline Motherboard form factor used to create PCs that
shadow mask CRT screen that allows only the proper electron gun to light the proper phosphors.
slot covers Metal plates that cover up unused expansion
share-level security Security system in which each
resource has a password assigned to it; access to the resource
is based on knowing the password.
Shared Documents Windows pre-made folder that is
accessible by all user accounts on the computer.
shared memory Means of reducing the amount of
memory needed on a video card by borrowing from the
regular system RAM, which reduces costs but also decreases
shareware Program protected by copyright; holder allows
(encourages!) you to make and distribute copies under the
condition that those who adopt the software after preview
pay a fee to the holder of the copyright. Derivative works are
not allowed, although you may make an archival copy.
shunt Tiny connector of metal enclosed in plastic that creates an electrical connection between two posts of a jumper.
were very thin. NLX and LPX were two examples of this
form factor.
slots on the back of a PC. Useful in maintaining proper airflow through a computer case.
smart battery Portable PC battery that tells the computer
when it needs to be charged, conditioned, or replaced.
smart card Hardware authentication involving a credit
card–sized card with circuitry that can be used to identify the
bearer of that card.
SmartMedia Format for flash media cards; no longer used
with new devices.
smartphone A cell phone enhanced to do things formerly
reserved for fully grown PCs, such as Web browsing, document viewing, and media consumption.
SMM (System Management Mode) Special CPU mode
that enables the CPU to reduce power consumption by selectively shutting down peripherals.
SMTP (Simple Mail Transport Protocol) Main protocol
used to send electronic mail on the Internet. Uses port 25.
snap-ins Small utilities that can be used with the Microsoft
Management Console.
snapshot Virtualization feature that enables you to save
an extra copy of the virtual machine as it is exactly at the
moment the snapshot is taken.
SNMP (Simple Network Management Protocol) A set
spyware Software that runs in the background of a user’s
PC, sending information about browsing habits back to the
company that installed it onto the system.
SRAM (static RAM) RAM that uses a flip-flop circuit
rather than the typical transistor/capacitor of DRAM to hold
a bit of information. SRAM does not need to be refreshed and
is faster than regular DRAM. Used primarily for cache.
of standards for communication with devices connected to a
TCP/IP network. Examples of these devices include routers,
hubs, and switches. Uses port 161.
SSD (solid-state drive) Data storage device that uses flash
social engineering Using or manipulating people inside
SSH (Secure Shell) Terminal emulation program similar
the networking environment to gain access to that network
from the outside.
to Telnet, except that the entire connection is encrypted. Uses
port 22.
socket services Device drivers that support the PC Card
socket, enabling the system to detect when a PC Card has
been inserted or removed, and providing the necessary I/O
to the device.
SSID (service set identifier) Parameter used to define a
SO-DIMM (small-outline DIMM) Memory used in portable PCs because of its small size.
soft power Characteristic of ATX motherboards, which can
use software to turn the PC on and off. The physical manifestation of soft power is the power switch. Instead of the thick
power cord used in AT systems, an ATX power switch is little
more than a pair of small wires leading to the motherboard.
software Single group of programs designed to do a par-
memory to store data.
wireless network; otherwise known as the network name.
SSL (Secure Sockets Layer) Security protocol used by a
browser to connect to secure Web sites.
standard user account User account in Windows Vista
that has limited access to a system. Accounts of this type
cannot alter system files, cannot install new programs, and
cannot edit some settings by using the Control Panel without
supplying an administrator password. Replaces the Limited
accounts in Windows XP.
standouts Small connectors that screw into a computer
ticular job; always stored on mass storage devices.
case. A motherboard is then placed on top of the standouts,
and small screws are used to secure it to the standouts.
solid core A cable that uses a single solid wire to transmit
star bus A hybrid network topology where the computers
all connect to a central bus—a switch—but otherwise take the
form of a star topology.
solid ink printers Printer that uses solid sticks of nontoxic
“ink” that produce vibrant color documents with much less
waste than color laser printers.
sound card Expansion card that can produce audible tones
when connected to a set of speakers.
Southbridge Part of a motherboard chipset; handles all the
inputs and outputs to the many devices in the PC.
spam Unsolicited e-mails from both legitimate businesses
and scammers that account for a huge percentage of traffic
on the Internet.
spanned volume Volume that uses space on multiple
dynamic disks.
SPD (serial presence detect) Information stored on a
star topology Network topology where the computers on
the network connect to a central wiring point, usually called
a hub.
Start button Button on the Windows taskbar that enables
access to the Start menu.
Start menu Menu that can be accessed by clicking the Start
button on the Windows taskbar. Enables you to see all programs loaded on the system and to start them.
Startup Repair A one-stop, do-it-all troubleshooting option
that performs a number of boot repairs automatically.
static charge eliminator Device used to remove a static
RAM chip that describes the speed, capacity, and other
aspects of the RAM chip.
static IP address Manually set IP address that will not
speaker Device that outputs sound by using magnetically
stealth virus Virus that uses various methods to hide from
driven diaphragm.
antivirus software.
sprite Bitmapped graphic such as a BMP file used by early
3-D games to create the 3-D world.
stepper motor One of two methods used to move actuator
arms in a hard drive. (See also voice coil motor.)
stereo Describes recording tracks from two sources (microphones) as opposed to monaural, which uses one source.
stick Generic name for a single physical SIMM, RIMM,
or DIMM.
swap file See page file.
swipe Gesture for mobile devices where you hold your
finger on the screen and slide it across the screen, either right
to left or top to bottom, depending on the type of application.
STP (shielded twisted pair) Cabling for networks, composed of pairs of wires twisted around each other at specific
intervals. Twists serve to reduce interference (also called
crosstalk)—the more twists, the less interference. Cable
has metallic shielding to protect the wires from external
switch Device that filters and forwards traffic based on
some criteria. A bridge and a router are both examples of
stranded core A cable that uses a bundle of tiny wire
sync The process of keeping files on mobile devices up to
date with the versions on desktop PCs or over the Internet.
strands to transmit signals. Stranded core is not quite as good
a conductor as solid core, but it will stand up to substantial
handling without breaking.
SXGA Video display mode of 1280 × 1024.
SXGA+ Video display mode of 1400 × 1050.
synchronize See sync.
stream loading Process a program uses to constantly
download updated information.
syntax The proper way to write a command-line com-
streaming media Broadcast of data that is played on your
Sysprep (System Preparation Tool) Windows tool that
makes cloning of systems easier by making it possible to
undo portions of the installation.
computer and immediately discarded.
stripe set Two or more drives in a group that are used for a
striped volume.
striped volume RAID 0 volumes. Data is spread across
two drives for increased speed.
mand so that it functions and does what it’s supposed to do.
system BIOS Primary set of BIOS stored on an EPROM or
flash ROM chip on the motherboard. Defines the BIOS for
all the assumed hardware on the motherboard, such as keyboard controller, floppy drive, basic video, and RAM.
strong password Password containing at least eight characters, including letters, numbers, and punctuation symbols.
system bus speed Speed at which the CPU and the rest of
structured cabling Standards defined by TIA/EIA that
define methods of organizing the cables in a network for ease
of repair and replacement.
system crystal Crystal that provides the speed signals for
stylus Pen-like input device used for pen-based
subnet mask Value used in TCP/IP settings to divide the
IP address of a host into its component parts: network ID and
host ID.
the PC operates; set by the system crystal.
the CPU and the rest of the system.
system disk Any device with a functional operating
system fan Any fan controlled by the motherboard but not
directly attached to the CPU.
System File Checker See sfc.
and columns between polarizing filters used in LCDs.
System Monitor Utility that can evaluate and monitor system resources, such as CPU usage and memory usage.
subwoofer Powerful speaker capable of producing
System Protection Feature in Windows Vista/7 that
sub-pixels Tiny liquid crystal molecules arranged in rows
extremely low-frequency sounds.
enables you to restore any previous version of a file or folder.
Super I/O chip Chip specially designed to control low-
system resources In classic terms, the I/O addresses,
IRQs, DMA channels, and memory addresses. Also refers to
other computer essentials such as hard drive space, system
RAM, and processor speed.
speed, legacy devices such as the keyboard, mouse, and
serial and parallel ports.
SuperSpeed USB A fast form of USB, with speeds up to
5 Gbps. Also called USB 3.0.
surge suppressor Inexpensive device that protects your
computer from voltage spikes.
SVGA (super video graphics array) Video display mode
of 800 × 600.
System Restore Utility in Windows that enables you to
return your PC to a recent working configuration when
something goes wrong. System Restore enables you to select
a restore point and then returns the computer’s system settings to the way they were at that restore point—all without
affecting your personal files or e-mail.
system ROM ROM chip that stores the system BIOS.
system setup utility See CMOS setup program.
System Tools Menu containing tools such as System Information and Disk Defragmenter, accessed by selecting Start |
Programs or All Programs | Accessories | System Tools.
system tray Contains icons representing background pro-
telecommunications room Area where all the cabling
from individual PCs in a network runs to.
telephone scams Social engineering attack in which the
attacker makes a phone call to someone in an organization to
gain information.
cesses and the system clock. Located by default at the right
edge of the Windows taskbar. Accurately called the notification area.
Telnet Terminal emulation program for TCP/IP networks
that allows one machine to control another as if the user were
sitting in front of it. Uses port 23.
system unit Main component of the PC, in which the CPU,
RAM, CD-ROM, and hard drive reside. All other devices—the
keyboard, mouse, and monitor—connect to the system unit.
Temporal Key Integrity Protocol (TKIP) Deprecated
encryption standard that provided a new encryption key for
every sent packet.
T568A Wiring standard for Ethernet cable.
tera- Prefix that usually stands for the binary number
T568B Wiring standard for Ethernet cable.
1,099,511,627,776 (240). When used for mass storage, it’s often
shorthand for 1 trillion bytes.
tablet A mobile device consisting of a large touchscreen,
enabling the user to browse the Web, view media, or even
play games.
Tablet PC Small portable computer distinguished by the
use of a touchscreen with stylus and handwriting recognition
as the primary modes of input. Also the name of the Windows XP–based operating system designed to run on such
tailgating Form of infiltration and social engineering that
involves following someone else through a door as if you
belong in the building.
Take Ownership Special permission allowing users to
seize control of a file or folder and potentially prevent others
from accessing the file/folder.
tap Touchscreen gesture where you press a spot on the
screen to start an app or interact with a running app.
terminal Dumb device connected to a mainframe or computer network that acts as a point for entry or retrieval of
terminal emulation Software that enables a PC to communicate with another computer or network as if the PC were a
specific type of hardware terminal.
termination Using terminating resistors to prevent packet
reflection on a network cable.
terminator Resistor that is plugged into the end of a bus
cable to absorb the excess electrical signal, preventing it from
bouncing back when it reaches the end of the wire. Terminators are used with coaxial cable and on the ends of SCSI
chains. RG-58 coaxial cable requires resistors with a 50-ohm
impedance. Also, a humanoid robot from the future designed
by Skynet to destroy all human life. He’ll be back.
den ones, and is accessed by pressing ctrl-shift-esc. Able to
shut down an unresponsive application that refuses to close
test the theory Attempt to resolve the issue by either confirming the theory and learning what needs to be done to fix
the problem, or by not confirming the theory and forming a
new one or escalating. (One of the steps a technician uses to
solve a problem.)
Task Scheduler Windows Vista/7’s utility enabling users
texture Small picture that is tiled over and over again on
Task Manager Shows all running programs, including hid-
to set tasks to run automatically at certain times.
walls, floors, and other surfaces to create the 3-D world.
taskbar Contains the Start button, the system tray, the
TFT (thin film transistor) Type of LCD screen. (See also
Quick Launch toolbar, and buttons for running applications.
Located by default at the bottom of the desktop.
tasklist A command-line version of the Task Manager.
TCP/IP (Transmission Control Protocol/Internet Protocol) Communication protocols developed by the U.S.
Department of Defense to enable dissimilar computers to
share information over a network.
tech toolkit Tools a PC tech should never be without,
including a Phillips-head screwdriver, a pair of tweezers,
a flat-head screwdriver, a hemostat, a Torx wrench, a parts
retriever, and a nut driver or two.
active matrix.)
theory of probable cause One possible reason why something is not working; a guess.
thermal compound Paste-like material with very high
heat-transfer properties. Applied between the CPU and the
cooling device, it ensures the best possible dispersal of heat
from the CPU. Also called heat dope.
thermal printer Printers that use heated printheads to
­create high-quality images on special or plain paper.
thermal unit Combination heat sink and fan designed for
BTX motherboards; blows hot air out the back of the case
instead of just into the case.
thick client CompTIA’s name for a standard desktop
thin client A system designed to handle only very basic
applications with an absolute minimum amount of hardware
required by the operating system.
thread Smallest logical division of a single program.
throttling Power reduction/thermal control capability
allowing CPUs to slow down during low activity or high
heat build-up situations. Intel’s version is known as SpeedStep, AMD’s as PowerNow!.
throw Size of the image a projector displays at a certain
distance from the screen.
TIA/EIA (Telecommunications Industry Association/
Electronic Industries Alliance) Trade organization that
provides standards for network cabling and other electronics.
tiers Levels of Internet providers, ranging from the Tier 1
backbones to Tier 3 regional networks.
timbre Qualities that differentiate the same note played on
different instruments.
tone generator See toner.
tone probe See toner.
toner A fine powder made up of plastic particles bonded
to iron particles, used to create the text and images on a laser
printer. Also, generic term for two devices used together—a
tone generator and a tone locator (probe)—to trace cables by
sending an electrical signal along a wire at a particular frequency. The tone locator then emits a sound when it distinguishes that frequency.
toner cartridge Object used to store the toner in a laser
printer. (See also laser printer, toner.)
topology The way computers connect to each other in a
touch interface The primary user interface on modern mobile devices where keys are replaced with tactile
touchpad Flat, touch-sensitive pad that serves as a pointing device for most laptops.
touchscreen Monitor with a type of sensing device across
its face that detects the location and duration of contact, usually by a finger or stylus.
tracert Command-line utility used to follow the path a
packet takes between two hosts. Also called traceroute.
traces Small electrical connections embedded in a circuit
track Area on a hard drive platter where data is stored. A
group of tracks with the same diameter is called a cylinder.
trackball Pointing device distinguished by a ball that is
rolled with the fingers.
TrackPoint IBM’s pencil eraser–sized joystick used in place
of a mouse on laptops.
transfer corona Thin wire, usually protected by other thin
wires, that applies a positive charge to the paper during the
laser printing process, drawing the negatively charged toner
particles off of the drum and onto the paper. Newer printers
accomplish the same feat using a transfer roller that draws the
toner onto the paper.
transparency Effect in the Aero desktop environment
(Windows Vista/7) that makes the edges of windows
triad Group of three phosphors—red, green, blue—in
a CRT.
Trojan horse Program that does something other than
what the user who runs the program thinks it will do. Used
to disguise malicious code.
troubleshooting theory Steps a technician uses to solve
a problem: identify the problem, establish a theory of probable cause, test the theory, establish and implement a plan of
action, verify functionality, and document findings.
Trusted Platform Module A hardware platform for the
acceleration of cryptographic functions and the secure storage of associated information.
tunneling Creating an encrypted link between two programs on two separate computers.
TV tuner Typically an add-on device that allows users to
watch television on a computer.
TWAIN (technology without an interesting name) Programming interface that enables a graphics application, such
as a desktop publishing program, to activate a scanner, frame
grabber, or other image-capturing device.
U (Units) The unique height measurement used with
equipment racks; 1 U equals 1.75 inches.
UAC (User Account Control) Windows Vista and Windows 7 feature that enables standard accounts to do common
tasks and provides a permissions dialog box when standard
and administrator accounts do certain things that could
potentially harm the computer (such as attempt to install a
UART (universal asynchronous receiver/transmitter) upgrade installation Installation of Windows on top of an
Device that turns serial data into parallel data. The cornerstone of serial ports and modems.
earlier installed version, thus inheriting all previous hardware and software settings.
UDF (universal data format) Replaced the ISO-9660 for-
UPS (uninterruptible power supply) Device that supplies
continuous clean power to a computer system the whole time
the computer is on. Protects against power outages and sags.
mats, enabling any operating system and optical drive to
read UDF formatted disks.
UEFI (Unified Extensible Firmware Interface) Consortium of companies that established the UEFI standard that
replaced the original EFI standard.
URL (uniform resource locator) An address that defines
the location of a resource on the Internet. URLs are used most
often in conjunction with HTML and the World Wide Web.
Ultra DMA Hard drive technology that enables drives
USB (universal serial bus) General-purpose serial inter-
to use direct memory addressing. Ultra DMA mode 3
drives—called ATA/33—have data transfer speeds up to 33
MBps. Mode 4 and 5 drives—called ATA/66 and ATA/100,
respectively—transfer data at up to 66 MBps for mode 4 and
100 MBps for mode 5. Mode 6 pushed the transfer rate to 133
MBps. Modes 4, 5, and 6 require an 80-wire cable and a compatible controller to achieve these data transfer rates.
connect for keyboards, printers, joysticks, and many other
devices. Enables hot-swapping of devices.
Ultrabook Thin, powerful laptop powered by Intel processors and built according to the Intel design specification.
Competes directly with the Apple Mac Air.
USB host controller Integrated circuit that is usually built
into the chipset and controls every USB device that connects
to it.
USB hub Device that extends a single USB connection to
two or more USB ports, almost always directly from one of
the USB ports connected to the root hub.
USB root hub Part of the host controller that makes the
unattended installation A type of OS installation where
physical connection to the USB ports.
special scripts perform all the OS setup duties without
human intervention.
USB thumb drive Flash memory device that uses the stan-
unauthorized access Anytime a person accesses resources
in an unauthorized way. This access may or may not be
user account Container that identifies a user to an application, operating system, or network, including name, password, user name, groups to which the user belongs, and
other information based on the user and the OS being used.
Usually defines the rights and roles a user plays on a system.
UNC (Universal Naming Convention) Describes any
shared resource in a network using the convention \\<server
name>\<name of shared resource>.
Unicode 16-bit code that covers every character of the most
common languages, plus several thousand symbols.
unsigned driver Driver that has not gone through the
Windows Certification Program to ensure compatibility.
The Windows Certification Program was formerly know as
the Windows Hardware Quality Labs and the Microsoft
Windows Logo Program.
UPC (Universal Product Code) Bar code used to track
update Individual fixes for Windows that come out fairly
often, on the order of once a week or so.
Upgrade Advisor The first process that runs on the Windows XP installation CD. It examines your hardware and
installed software (in the case of an upgrade) and provides
a list of devices and software that are known to have issues
with XP. It can also be run separately from the Windows XP
installation, from the Windows XP CD. The Upgrade Advisor
is also available for Windows Vista and Windows 7.
dard USB connection.
User Accounts applet Windows XP (and later versions)
applet for creating and modifying user accounts.
user interface Visual representation of the computer on
the monitor that makes sense to the people using the computer, through which the user can interact with the computer.
This can be a graphical user interface (GUI) like Windows 7
or a command-line interface like the Windows PowerShell or
the Recovery Console.
user profiles Settings that correspond to a specific user
account and may follow users regardless of the computers
where they log on. These settings enable the user to have customized environment and security settings.
User’s Files Windows Vista and Windows 7 default location for content specific to each user account on a computer.
It is divided into several folders such as Documents, Pictures,
Music, and Video. Similar to My Documents folder structure
in Windows XP.
Users and Passwords applet Windows 2000 application
that allowed management of user accounts and passwords.
Users group List of local users not allowed, among other
things, to edit the Registry or access critical system files.
They can create groups, but can only manage the groups they
USMT (User State Migration Tool) Advanced application for file and settings transfer of multiple users.
UTP (unshielded twisted pair) Popular type of cabling
for telephone and networks, composed of pairs of wires
twisted around each other at specific intervals. The twists
serve to reduce interference (also called crosstalk). The more
twists, the less interference. Unlike its cousin, STP, UTP cable
has no metallic shielding to protect the wires from external
interference. 1000BaseT uses UTP, as do many other networking technologies. UTP is available in a variety of grades,
called categories, as follows:
CAT 1 UTP Regular analog phone lines—not used for data
CAT 2 UTP Supports speeds up to 4 megabits per second.
CAT 3 UTP Supports speeds up to 16 megabits per second.
CAT 4 UTP Supports speeds up to 20 megabits per second.
CAT 5 UTP Supports speeds up to 100 megabits per second.
CAT 5e UTP Supports speeds up to 1000 megabits per
CAT 6 UTP Supports speeds up to 10 gigabits per second.
CAT 6a UTP Supports speeds up to 10 gigabits per second.
virtual machine (VM) A complete environment for a
guest operating system to function as though that operating
system were installed on its own computer.
virtual machine manager (VMM) See hypervisor.
virus Program that can make a copy of itself without your
necessarily being aware of it. Some viruses can destroy or
damage files. The best protection is to back up files regularly.
virus definition or data file Files that enable the virus
protection software to recognize the viruses on your system
and clean them. These files should be updated often. They
are also called signature files, depending on the virus protection software in use.
virus shield Passive monitoring of a computer’s activity,
checking for viruses only when certain events occur.
VIS (viewable image size) Measurement of the viewable
image that is displayed by a CRT rather than a measurement
of the CRT itself.
voice coil motor One of two methods used to move actuator arms in a hard drive. (See also stepper motor.)
VoIP (Voice over Internet Protocol) Collection of protocols that make voice calls over a data network possible.
volatile Memory that must have constant electricity to
manufacturers to follow (voluntarily) to ensure compatible
speeds, compression, and error correction.
retain data. Alternatively, any programmer six hours before
deadline after a nonstop, 48-hour coding session, running on
nothing but caffeine and sugar.
vendor specific Stores that only sell products from one
manufacturer, like the Apple store.
volts (V) Measurement of the pressure of the electrons
passing through a wire, or voltage.
verify full system functionality Making sure that a problem has been resolved and will not return. (One of the steps a
technician uses to solve a problem.)
volume Physical unit of a storage medium, such as tape
reel or disk pack, that is capable of having data recorded on it
and subsequently read. Also, a contiguous collection of cylinders or blocks on a disk that are treated as a separate unit.
V standards Standards established by CCITT for modem
vertices Used in the second generation of 3-D rendering;
have a defined X, Y, and Z position in a 3-D world.
VESA (Video Electronics Standards Association) Consortium of computer manufacturers that standardize
improvements to common IBM PC components. VESA is
responsible for the Super VGA video standard and the VLB
bus architecture.
VGA (video graphics array) Standard for the video graphics adapter that was built into IBM’s PS/2 computer. It supports 16 colors in a 640 × 480 pixel video display.
video capture Computer jargon for the recording of video
information, such as TV shows or movies.
video card Expansion card that works with the CPU to
produce the images displayed on your computer’s display.
video display See monitor.
volume boot sector First sector of the first cylinder of each
partition; stores information important to its partition, such
as the location of the operating system boot files.
voucher Means of getting a discount on the CompTIA A+
VPN (Virtual Private Network) Encrypted connection
over the Internet between a computer or remote network and
a private network.
VRM (voltage regulator module) Small card supplied
with some CPUs to ensure that the CPU gets correct voltage.
This type of card, which must be used with a motherboard
specially designed to accept it, is not commonly seen today.
VRR (vertical refresh rate) The amount of time it takes
for a CRT to draw a complete screen. This value is measured
in hertz, or cycles per second. Most modern CRTs have a
VRR of 60 Hz or better.
wait state Occurs when the CPU has to wait for RAM to
provide code. Also known as pipeline stall.
WAP (wireless access point) Device that centrally connects wireless network nodes.
wattage (watts or W) Measurement of the amps and
volts needed for a particular device to function.
wave table synthesis Technique that supplanted FM
synthesis, wherein recordings of actual instruments or other
sounds are embedded in the sound card as WAV files. When
a particular note from a particular instrument or voice is
requested, the sound processor grabs the appropriate prerecorded WAV file from its memory and adjusts it to match the
specific sound and timing requested.
Web browser Program designed to retrieve, interpret, and
display Web pages.
Web server A computer that stores and shares the files
Windows 7 Version of Windows; comes in many different
editions for home and office use, but does not have a Server
Windows 7 Compatibility Center Microsoft’s current
Web site that lists the hardware and software that work with
Windows 7.
Windows 8 Version of Windows noted for the Metro
interface. Used for desktop and portable PCs and for mobile
Windows 9x Term used collectively for Windows 95,
­Windows 98, Windows 98 SE, and Windows Me.
Windows Certification Program A rigorous testing program for hardware manufacturers. Hardware and drivers
that survive the testing get to wear the Designed for Windows
logo. The drivers get a digital signature that says Microsoft
tested them and found all was well.
Windows Easy Transfer Windows Vista/7’s method of
transferring files and settings to a new PC.
that make up Web sites.
Windows Explorer Windows utility that enables you to
webcam PC camera most commonly used for Internet
manipulate files and folders stored on the drives in your
Welcome screen Logon screen for Windows XP. Enables
users to select their particular user account by clicking on
their user picture.
WEP (Wired Equivalent Privacy) Wireless security protocol that uses a standard 40-bit encryption to scramble data
packets. Does not provide complete end-to-end encryption
and is vulnerable to attack.
Wi-Fi Common name for the IEEE 802.11 wireless Ethernet
Wi-Fi Protected Setup (WPS) A standard included on
many WAPs and clients to make secure connections easier to
wide area network (WAN) A widespread group of computers connected using long-distance technologies.
wildcard Character used during a search to represent
search criteria. For instance, searching for *.doc will return
a list of all files with a .doc extension, regardless of the filename. The * is the wildcard in that search.
WiMAX (Worldwide Interoperability for Microwave
Access) An updated wireless standard (also known as
802.16) with a range of up to 30 miles.
Windows 2000 Windows version that succeeded Windows NT; it came in both Professional and Server versions.
Windows Logo’d Products List List of products that have
passed the Microsoft Windows Logo Program and are compatible with Windows operating system. Formerly called the
Hardware Compatibility List (or HCL).
Windows NT Precursor to Windows 2000, XP, Vista, and
7, which introduced many important features (such as HAL
and NTFS) used in all later versions of Windows.
Windows PowerShell Command-line tool included with
Windows 7 and available for earlier versions from Microsoft.
Offers a number of powerful scripting tools for automating
changes both on local machines and over networks.
Windows Preinstallation Environment (WinPE) The
installation program for Windows Vista and 7.
Windows Recovery Environment (WinRE) An special
set of tools in the Windows Vista/7 setup that enables you to
access troubleshooting and repair features.
Windows Sidebar User interface feature in Windows
Vista that enables users to place various gadgets, such as
clocks, calendars, and other utilities, on the right side of their
Windows Update Microsoft application used to keep Windows operating systems up to date with the latest patches or
enhancements. (See Automatic Updates.)
Windows Vista Version of Windows; comes in many different editions for home and office use, but does not have a
Server edition.
Windows XP Version of Windows that replaced both the
entire Windows 9x line and Windows 2000; does not have a
Server version.
Windows XP Mode A Windows XP virtual machine that
ships with Professional, Enterprise, and Ultimate editions of
Windows 7 to enable users to run programs that don’t work
on Windows 7.
work area In a basic structured cabling network, often
simply an office or cubicle that potentially contains a PC
attached to the network.
workgroup A simple, decentralized network that Windows
PCs are configured to use by default.
worm Very special form of virus. Unlike other viruses, a
worm does not infect other files on the computer. Instead, it
replicates by making copies of itself on other systems on a
network by taking advantage of security weaknesses in networking protocols.
WPA (Wi-Fi Protected Access) Wireless security protocol that uses encryption key integrity-checking and EAP and
is designed to improve on WEP’s weaknesses.
WPA 2 (Wi-Fi Protected Access 2) Wireless security
protocol, also known as IEEE 802.11i. Uses the Advanced
Encryption Standard (AES) and replaces WPA.
WQUXGA Video display mode of 2560 × 1600.
wrapper See container file.
WSXGA Video display mode of 1440 × 900.
WSXGA+ Video display mode of 1680 × 1050.
WVGA Video display mode of 800 × 480.
WWW (World Wide Web) System of Internet servers
that supports documents formatted in HTML and related
protocols. Can be accessed by applications that use HTTP
and HTTPS, such as Web browsers. CompTIA’s Web site.
WXGA Video display mode of 1280 × 800.
x64 Describes 64-bit operating systems and software.
x86 Describes 32-bit operating systems and software.
xcopy command Command in the command-line interface
used to copy multiple directories at once, which the copy
command could not do.
xD (Extreme Digital) picture card Very small flash media
card format.
Xeon Line of Intel CPUs designed for servers.
XGA (extended graphics array) Video display mode of
1024 × 768.
XPS (XML Paper Specification) print path Improved
printing subsystem included in Windows Vista. Has
enhanced color management and better print layout fidelity.
XT bus See PC bus.
ZIF (zero insertion force) socket Socket for CPUs that
enables insertion of a chip without the need to apply pressure. Intel promoted this socket with its overdrive upgrades.
The chip drops effortlessly into the socket’s holes, and a
small lever locks it in.
WUXGA Video display mode of 1920 × 1200.
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