INDUSTRY
GLOSSARY
Accelerated Graphics Port (AGP)
A high-speed graphics port that allows fast
communication between the graphics controller and computer. This port runs at
least twice as fast as older Peripheral Component Interconnect (PCI) video cards
and allows the graphic card to directly access the computer’s main memory. ACP
allows 3-D textures for texture mapping to be stored in main memory, while PCI
graphics cards allow textures to be stored only in the smaller video memory. The
AGP port also bypasses the PCI bus, through which traffic can be heavy, since it
is also used by network cards, some modems, SCSI adapters, and other add-in
cards. Thus, with AGP, performance is improved for both the graphics card and
PCI bus. AGP requires a motherboard that supports Pentium II or certain AMD or
Cyrix chips and contains and AGP slot. Windows 95 OSR 2.1 or Windows 98 also is
required. To see if you have the required version of Windows 95, click Control
Panel, System, and select the General tab. If you have the “Microsoft Windows
95 4.00.950 B” or “40.00.950.1111.” See Peripheral Component
Interconnect (PCI). See texture mapping.
ATA - Advanced
Technology Attachment
See Integrated
Drive Electronics.
Active-matrix Display
A flat-panel display used in many notebook
computers in which every pixel (tiny picture elements) is controlled and
adjusted by its own transistor, which creates a sharp image. Active-matrix
screens are more expensive to produce than other major types of displays for
portable PCs. Compare to passive-matrix display.
ADSL - Asymmetric
Digital Subscriber Line
A Digital Subscriber Line (DSL) on which
data flows in (downstream) faster than it goes out (upstream). ADSL
speeds range from 1.5 megabits per second (Mbps) to 6Mbps downstream and 64
kilobits per second (Kbps) to 384 Kbps upstream. These rates reflect the fact
that Internet. Use requires more downstream than upstream bandwidth, since
loading Web pages is a downstream activity. Someone running Web server,
however, also would need a wide upstream pipe. ADSL also has become a generic
reference to all DSL lines, even though it is quite different than the other
types of DSL lines. See bandwidth and Digital Subscriber Line (DSL).
BIOS – Basic
Input/Output System (Pronounced
Bye-ose).
A special piece of software built into most
computers. BIOS routines control the startup process of the machines and other
basic functions such as the keyboards, display, and disk drives. On older
computers, the BIOS is stored in read-only memory, which is not erased when the
power to the computer is shut off. Newer computers store BIOS on flash ROM,
which can be erased and rewritten if the user needs to update the BIOS program.
Bandwidth
The capacity a network or data connection has
for carrying data. For analog transmission, bandwidth is the difference between
the upper and lower transmission frequencies in a given range. It is measured in
cycles per second or hertz (Hz). For digital transmission, bandwidth is measured
in bits per second (bps), the larger the bandwidth number, and the faster the
digital transmission. The speed is important for input/output devices because a
bus with a low bandwidth could restrain a faster I/O device from performing at
full capacity.
Baseband transmission
Communication in which the wire or line carries
one signal at a time. Until recently, most communication systems used baseband
transmission. The trend for the future is to move to broadband transmission.
Broadband transmission
Communication in which the wire or line can
transmit several data streams simultaneously. One example is the coaxial cable
used in cable television systems, which carries multiple channels at once. More
recently, broadband has come to describe high-speed data transmission,
especially over the Internet, sufficient to carry live video on demand. Compare
to baseband transmission.
Bus
The electronic connection linking electronic
devices such as the internal sections of a computer (e.g., the simultaneously
transported CPU, expansion cards, and peripherals). The amount of data that can
be along a bus is determined by the number of connections for moving binary
numbers. For instance, a 16-bit bus can transport up to 16 ones and zeros
(binary digits) at once. Popular types of buses include Peripheral Component
Interconnect (PCI) and Small Computer System Interface (SCSI). In networks, a
bus is the cable system known as the backbone, which connects all computers into
a single network.
See
bus width. See
Peripheral Component Interconnect. See Small Computer System Interface.
Bus Width
The amount of data a bus can handle at one
time. Many buses are either 16-bit or 32-bit, meaning they can transmit 16 or 32
bits simultaneously. The more bits a bus can handle, the more data can be
transmitted at any one time, allowing the computer to perform tasks more
quickly.
CD-R Drive
A drive that can read and write CDs, allowing
users to create CD-ROMs. Unlike the CD-erasable format, these discs, once
recorded, can’t be erased and reused, although the information can be stored
in numerous sessions (if the disc is not filled in the first session). CD-R
drives can play CD-ROMs and CD-R discs, and CD-R discs can be played in (but not
written to) CD-ROM drives. CD-R discs have a blue-green tinge because the
material on the discs is a dye polymer. When information is recorded, a laser in
the CD-R drive heats up the dye material, altering the reflection of the
returned light. The different colors of returned light is how the drive reads
the 0s and 1s, or ons and offs, of data. This is why recording a CD-R disc is
called burning a CD.
CPU – Central
Processing Unit
The computer’s control unit, or
microprocessor is its brain. The CPU is a silicon chip often enclosed in a
plastic casing, which interprets and carries out instructions. The first CPU was
an 8080 processor from Intel, introduced in 1974.
It had an eight-bit data bus, which meant it
could transfer eight bits of data to and from the CPU, and it used eight bits to
address memory locations. In 1978, Intel introduced the 8086 and 8088, with
16-bit registers, which allowed the chips to process 16 bits of information at a
time. The chips also had 20-bit memory addressing. The 8088 had an eight-bit
bus, while the 8086 had a 16-bit bus. Next came the 80286, called the 286, in
1982. It had a 16-bit data bus, 16-bit registers, and 24-bit memory addressing.
The 386 generation was the first to have two types, the 386X and the 386DX. The
386DX came first and was a full 32-bit microprocessor. That means it had 32-bit
registers, a 32-bit data bus and 32-bit memory addressing. The 386SX, a less
expensive version introduced in 1988, had only a 16-bit data bus. The 486DX,
introduced in 1989, was still a 32-bit processor but had enhancements that
resulted in better performance. The 486SX also was a full 32-bit processor but
lacked the math coprocessor present in the 486DX.
The 486DX2, introduced in 1992, used
clock-doubling to double the speed of all the microprocessor’s internal
operations. The Pentium, introduced in 1993, has a 32-bit address bus but a
64-bit data bus. Pentium II and Pentium III are Intel’s latest advances. A
CPU’s clock speed determines how fast it performs calculations; the 80286, for
instance, could run at up to 12MHz while a new Pentium chip might run at up to
550MHz. Although most IBM-compatible PC’s use Intel CPU’s, other companies
such as Cyrix and AMD also produce compatible microprocessors able to run nearly
all of the same software. Intel’s position as the dominant CPU manufacturer
has allowed it to determine, to a large extent, the direction of the computer
industry.
CRT – Cathode-ray
tube
The display screen used in most televisions and
standard computer monitors. An electron beam moves across the back of the
screen, lighting up phosphor dots inside the glass tube, which cause an image to
be displayed.
CMSA/CA – Carrier Sense Multiple Access/Collision Avoidance
In network systems, a method of avoiding conflicts between messages sent on the network. When a node on a network with CSMA/CA is about to send a message, it sends a jam signal, waits a moment, and then starts to transmit the message. If during the transmission of a message the network detects another node’s jam signal, indicating that a second message is about to be sent, the second transmission is stopped, and the second node waits a random length of time before trying again.
Daisy Chain
A set of hardware components connected to each
other in a series. The first component connects to the computer, the second
component connects to the first, and so on. Signals are passed from the computer
to the first device and on through the line. To limit confusion, each device is
given a different priority to use the channel to which they are all connected,
or they transmit information only when they “hear” that the line is clear.
This eliminates disorder and conflicting requests. The small Computer System
Interface (SCSI), for example, is a daisy chain system that supports up to seven
devices. “Daisy chain” is also used as a verb to describe the action of
connecting devices in that pattern. See Small Computer System Interface
(SCSI).
Data Compression
Any method of condensing information so it can
be stored in less space or transmitted in less time. Many large graphics and
sound files are compressed so they can be downloaded faster. Although data
compression can be done in many ways, a compression program generally looks for
redundancies in a file, then compresses the identical pieces of data into one
representative token. Also called data compaction. Also referred to as file
compression. See ZIP files.
DIP - Dual Inline
Package
A tiny hard-plastic housing unit generally used
to encase integrated circuits in older-model computers. The casing made it
easier to solder the circuits onto a circuit board. Newer computers require too
many connections to make DIP feasible.
DSL – Digital
Subscriber Line
Technology used to transmit digital data on
regular copper phone lines. DSLs can be used to provide connections to the
Internet or Local-area Networks (LANs) or for video-conferencing. The
technology differs from Integrated Services Digital Network (ISDN) lines
in that it can send analog and digital signals over the phone line. ISDN is
digital only and has to convert analog voice phone calls to digital signals.
With DSL, the analog voice phone calls and digital signals can coexist on the
same wires. This works because analog signals require only a fraction of the
capacity of the copper wires that make up a phone line. The limitation of the
analog signal carried on those wires, not the wires themselves, has kept phone
lines from delivering greater data transfer speeds. Sending digital signals over
copper wire breaks that barrier. See Asymmetric Digital Subscriber Line. See
Integrated Services Digital Network. See Local-area Networks.
Dual-scan Display
A type of passive-matrix display used mainly in
portable computers that allows a screen to be refreshed twice as often as the
regular passive-matrix display. Dual-scan displays, although higher in quality
than regular passive-matrix display, are still not of the same quality as
active-matrix displays. Also called double-scan display. See active-matrix
display. See passive-matrix display.
DIP – Dual Inline
Package
A tiny hard plastic housing unit generally used
to encase integrated circuits in older-model computers. The casing made it
easier to solder the circuits onto a circuit board. Newer computers require too
many connections to make a DIP feasible.
EISA - Extended Industry Standard Architecture
Known as extended ISA, sometimes pronounced “eesah.”
The standard for an IBM-compatible computer data bus that can transfer 32 bits
of data at one time. The Extended ISA was developed by a consortium of nine IBM
competitors as a response to IBM’s Micro Channel Architecture (MCA) bus.
Neither MCA nor EISA really ever caught on. Today’s Pentium PCs often feature
a combination of ISA expansion card slots and the new Peripheral Component
Interconnect – PCI slots. See expansion card. See Industry
Standard Architecture. See Micro-Channel Architecture. See Peripheral
Component Interconnect.
Ergonomic(s)
The study or science of how people interact
with their work areas. Ergonomics can help determine the proper setup of a
chair, desk, or monitor height. It also can suggest the position of the hands on
the keyboard or how to get rid of glare on a screen. The goal is to keep things
as comfortable and effective as possible. Ergonomics became common in the
1990’s because computers became a prevalent part of the office. Improper
ergonomics may cause carpel tunnel syndrome and other repetitive stress injuries
and conditions.
Ethernet
The most
widely used local-area network (LAN) protocol, Ethernet was created by Xerox in
1976. Later the standard was rewritten by Xerox along with Digital Equipment
Corporation and Intel. Ethernet is the original carrier sense multiple
access/collision avoidance (CSMA/CA) LAN that lets PCs connected to the
network listen for pauses before they “speak.” Older Ethernet networks used
either thin or thick coaxial cable to connect computers together. A newer system
called 10Base-T uses wiring similar to that used in telephone systems and
transfers data at up to 10 megabits per second. Fast Ethernet, knows as
100Base-T, allows transfers at 100 megabits per second. Fiber optic Ethernet
variations also let users extend network capabilities far from the base site. See
carrier sense multiple access/collision avoidance. See local-area
network.
Expansion Card
An add-on
electronic circuit board that gives a computer new abilities. Expansion cards
are used to connect devices such as fax/modems, sound cards, graphics cards,
hard drive and CD-ROM drive controllers, mice or extra ports to a PC. They fit
into expansion slots on the motherboard inside the computer’s casing. Portable
computers use a special kind of expansion card called a PC Card, which fits into
a PC Card slot in the portable computer. Also called an expansion board. See
Expansion Slot. See PC Card.
Expansion Slot
A slot or
socket inside a computer allowing the installation of add-on expansion cards.
Such cards give the computer new abilities or otherwise improve operation. The
slot is actually an outlet on the motherboard providing a direct connection
between the computer’s bus, or main data pathway, and the expansion card.
Expansion cards must be made to fit the various types of expansion slots. The
main types of expansion slots are Video Electronics Standards Association
Local Bus – VL-bus, Industry Standard Architecture – ISA, Extended Industry
Standard Architecture – EISA and Peripheral Component Interconnect –
PCI. See expansion card. See Industry
Standard Architecture – ISA. See Video Electronics Standards
Association. See Local Bus.
File
Compression
See data compression. See zip
files.
Hot-swapping
Means to replace a computer component while the
computer’s power is switched on. This ability is especially important for
mainframe computers or servers in a client-server system that cannot afford
downtime. These computers generally have redundant parts such as hard drives and
power supplies to ensure reliability, and these parts can be switched out if
they fail. Storage systems on client-server networks also often use hot-swap
functions for the same reasons. For personal computers, the advent of the USB
– universal serial bus – standard lets users hot swap peripherals into the
USB port and have the computer automatically recognize them without rebooting.
IEEE 1394
A specification for a new, high-speed external
bus used to connect computer peripherals. The cost of using this bus is still
very high for all but those peripherals that demand high
external bus speeds for bandwidth- consuming
multimedia, such as digital cameras, digital VCRs and Digital Video Disc (DVD)
players. For other external bus devices, such as mice and keyboards, the
Universal Serial Bus (USB) is more economical even though it operates at lower
speed. IEEE 1394, developed at Apple Computers and dubbed FireWire, boasts
transfer speeds up to 400 megabits per second (Mbps) and can handle up to 63
devices. Other benefits include Plug and Play (PnP), hot-swapping, and support
for a constant transmission speed, which is appropriate for streaming audio and
video content because it doesn’t handle changes in speed well. Though
developed at Apple, the technology works on Macintosh computers. See hot-swapping.
ISA – Industry Standard Architecture
The standard
bus modeled after IBM’s original 8-bit PC bus. In 1984, ISA was expanded to a
16-bit capability. The ISA standard allows users to add 16-bit expansion cards
to special slots built into the motherboard. Though the ISA bus is outdated
today, most computers still include a few ISA expansion slots to accommodate the
large number of ISA-compatible expansion boards in existence. See
expansion slot. See motherboard.
ISDN – Integrated
Services Digital Network
A telecommunications network that allows for
digital voice, video and data transmissions. ISDN replaces the slow and
inefficient analog telephone system with a fast and efficient digital
communications network. ISDN lines contain two channels: a B channel, which has
a 64 kilobits per second (Kbps) data transmission rate, and a D channel, which
has either a 16Kbps or 64Kbps transmission rate. When the two lines are used
together, transmitted data can travel at 128Kbps. Connecting to an ISDN line
requires a network terminator and an ISDN terminal adapter. A network terminator
prepares a standard telephone line for ISDN data transmission. An ISDN terminal
adapter prepares the computer for ISDN transmissions. ISDN lines are available
from most phone companies throughout the world, but they cost more than a
standard phone service. Prices are dropping, however, and ISDN lines may soon
become as affordable as other communications services.
LAN – Local Area
Network
A group of computers, usually in one building
or office, physically connected in a manner that lets them communicate and
interact with each other. For a network to operate, it needs a server, which is
a computer that holds data used by the different computers on the network. Some
of the benefits of a network connection include the ability to share document
files and expensive equipment, such as laser printers. Networks can be connected
using different combinations of topologies, protocols, software and hardware. Compare
wide-area network.
LOCAL AREA WIRELESS
NETWORK (LAWN)
A network that
uses radio transmissions instead of cables to connect computers. A LAWN shares
many capabilities with a local-area network (LAN). See
Local Area Network – LAN.
LCD – Liquid-crystal
Display
A flat, light-weight display technology used in
calculators and laptop computers. Special molecules in the screen have the
ability to bend and twist light to create desired images.
There are monochrome LCD displays, which appear
gray, and there are color LCDs. The three basic types of LCD displays are
passive-matrix, dual-scan and active-matrix. Active-matrix displays look the
best, but they are much more expensive than dual-scan and passive-matrix
displays. See active-matrix display. See dual-scan display.
See passive-matrix display.
Motherboard
The printed circuit board that is the foundation of any computer. This board contains a computer’s CPU, RAM chips, and expansion slots. The motherboard is where all of the computer’s components meet. Also called system board or mainboard.
Network
A set of conjoined computers that can share
storage devices, peripherals and applications. Networks may be connected
directly by cable connection, or indirectly by telephone lines or satellites and
can be part of a small-office system or a global web of numerous
other networks.
NIC – Network
Interface Card (Pronounced Nick).
A printed circuit board containing the
necessary hardware used to connect a computer to a network. See network.
OCR – Optical
Character Recognition
The process in which the images of letters,
entered into a computer with a scanner, are translated into characters that are
worked with in the computer as text, not as an image. OCR is far from perfect,
but it is a fast method for digitizing typed pages of text. Some computer fax
applications also use OCR to transform incoming faxes from graphics files to
word processing documents.
OS (Operating System)
Software that controls a computer and its
peripherals. Early OSes, such as DOS and Unix, left a great deal of the
operation up to the user, but later OSes, such as OS/2 and Windows 95, handle
many of a computer’s basic functions.
Passive-matrix Display
A type of screen display most commonly used for
portable computers that use liquid-crystal display (LCD) technology. A
passive-matrix display has a series of criss-crossed wires with an LCD element
at each intersection. Each of those LCD elements amounts to a single pixel that
can either allow light to pass or not. A passive-matrix display cannot produce
the same level of quality image an active-matrix display can. Compare to active-matrix
display. See liquid-crystal display.
PC Card
A credit card-sized
device that plugs into a PC Card slot on the motherboard and enables the user to
add additional computer peripherals including modems, sound cards, and CD-ROM
devices. They are used primarily in portable computers but can be used in
desk-top systems as well. There are three sizes of PC Cards: Type I cards (3.3mm
thick) often are used for adding RAM and ROM. Type II cards (5mm thick) usually
used for adding modems; and Type III cards (10.5mm thick) which are sometimes
used for adding a portable disk drive. Developed by the Personal Computer
Memory Card International Association (PCMCIA), PC Cards were originally
called PMCIA cards.
PCI – Peripheral
Component Interconnect
The Intel local bus standard that allows for
faster communication between a CPU and peripheral components, thus speeding up
operating time. Most PCI buses coexist on a motherboard with an Industry
Standard Architecture (ISA) or Extended Industry Standard Architecture (EISA)
bus, so that the user can plug in expansion cards compatible with either
standard. An advantage to the PCI bus is its Plug-and-Play capability, which
means it can help an operating system such as Windows 95 detect and configure
new cards when they are placed in a PCI slot. See CPU. See Plug and
Play.
PDA - Personal Digital
Assistant
Otherwise known as a Palmtop computer. This is
a PC that fits in the palm of the user’s hand. In the past, nearly all
palmtop computers had relatively limited
capabilities, mainly because of their severely limited amount of storage space
and their inability to easily connect to desktop PC’s.
Most of the early palmtops served as high-tech
message pads and personal telephone books. Today’s palmtops offer improvements
in handwriting recognition software, thus making them easier to use than their
predecessors. Also, the newest palmtops connect easily to larger PCs and
exchange information. New palmtops don’t even need to physically connect to
desktop computer to transfer information, the Palm Pilot and Windows CE-based
devices are equipped with an infrared transmitter for connections when the unit
is set next to the desktop. Some palmtops come equipped
with basic word processing or spreadsheet
programs and modems for sending and receiving faxes and e-mail messages. Also
referred to as hand-held computers or personal digital assistants (PDAs).
(PnP) Plug and Play
The ability of a computer to detect and
configure new hardware automatically, with almost no intervention on the part of
the user. Apple’s Mackintosh computers have long used Plug and Play
technology, but PC users had to wait until Windows 95 brought a Microsoft-Intel
version of PnP to their machines. Without Plug and Play, it is often
necessary to manually change hardware settings
in order for the computer to recognize the new component. That usually means
resetting tiny jumpers or dual inline package (DIP) switches. When a
computer is equipped with a PnP operating system such as Win95 and a PnP BIOS on
the motherboard, it is a simple process to have the machine find PnP devices
such as modems, sound cards, and other components on its own.
SCS – SCS1 –
SCSI-2 (Small Computer Systems)
A standard for parallel interfaces that
transfer information at rates of up to 80 megabytes (MBps) per second. The
SCSI-2 can transfer up to 40 megabytes of data per second on a 16-bit or 32-bit
bus system, considerably faster than its predecessor. The improved interface was
also designed to correct some of the incompatibility problems SCSI had with
adding additional devices. With SCSI-2, scanners, hard drives and CD-ROM drives,
as well as other devices, are now more easily connected. See Small
Computer System Interface.
SEA –
Self-extracting File
A compressed file, usually denoted by the file
extension, SEA that includes the necessary executable program to decompress
itself upon command. Normally, executing such a file will begin the
decompression process. See file compression. See data compression. See
zip files.
Small Computer System
Interface (SCSI –
pronounced scuz-zee).
A standard for parallel interfaces that
transfer information at rates of up to 80 megabytes per second to seven
peripheral devices, such as a hard drive and CD-ROM drive, can attach to a
single SCSI port on the system’s bus. SCSI ports were designed for Apple
Macintosh and Unix computers, but also can be used with properly equipped
PC’s.
SOHO – Small
Office-Home Office (Pronounced So-hoe).
A target computer market consisting of users
who work at home or in small businesses.
Teleco
Is to work at home and communicate with an
office via Telecommunications lines. Telecommuting is increasingly popular as
the technology that allows workers to telecommute effectively becomes available.
Many companies allow workers to telecommute a few days a week, but require them
to work in the office much of the time as well. There are several benefits to
telecommuting; increased productivity and time savings are the most commonly
cited benefits for companies, while comfort and convenience rank high among
telecommuters. Drawbacks such as distractions and lessened communication with
co-workers, however, do exist.
Texture Mapping
To give surface texture to an image in a
computer graphics program.
TFT – Thin Film
Transistor
Sometimes called active-matrix liquid-crystal
displays (LCDs). A type of flat-panel PC screen used on portable computers. Each
pixel is controlled by between one and four transistors, making TFT screens
faster, brighter and more colorful than passive-matrix screens, which use a grid
of transistors to turn rows and columns of pixels on and off.
TFT provides the best resolution of any
flat-panel technique, but is also the most expensive technology. See active-matrix
display. See liquid-crystal display.
Unzip
To decompress a file with PKWARE Inc.’s
PKUNZIP software package. Files are often zipped (compressed) before they are
sent to another PC via an online service or through the Internet so they don’t
take as long to transmit and download. When zipped files reach their
destination, they must be unzipped (uncompressed) before they can be used. Compare
to Zip.
USB – Universal
Serial Bus
A new type of external bus, which is now
replacing parallel and serial ports. With a maximum transfer speed of 12
megabits per second (Mbps), USB is designed primarily for low- to mid-speed
peripheral devices, such as keyboards, mice, modems, printers, joysticks and
some scanners. More bandwidth-intensive devices, such as digital video cameras
and storage devices, will soon all be using
IEEE 1394 (FireWire) as standard. A main advantage of USB over
traditional ports is that it can easily be expanded: up
to 127 devices can be daisy chained, far more
than the number of devices supported by traditional ports. All USB devices
support plug and play (PnP) and hot swapping as well. The computer automatically
recognizes any USB device as soon as it’s plugged in or added to the chain.
Desktop computers that support USB typically have two four-pin USB ports – one
for a keyboard and mouse daisy chain, the other to daisy chain all other USB
devices. USB was introduced in computers shipped during 1997 and has received a
boost from Windows 98, which offers better support for the standard that Windows
95 established. Mackintosh computers are expected to support the standard. The
iMac, for example, has no serial or Small Computer System Interface (SCSI)
ports, only USB ports. See bandwidth. See daisy chain.
VESA – Video Electronics Standards Association (pronounced vee-sah)
A group of monitor and video card manufacturers that set standards for high-resolution monitors and video cards. Buying products that follow VESA standards makes it easier to ensure the components of a system work together.
VPN - Virtual Private
Network
To better explain what this means, let us break
down the phrase, first of all, explain the meaning of virtual – This
word is generally used to describe something without a physical presence or is
not what it appears to be. For example, virtual reality is made up of
computer-generated images and sounds rather than actual objects. Virtual
memory, on the other hand, is a hard drive acting as memory; it’s not the
physical chips used in real memory. A private line is leased by a private
individual or company from a telephone company. This line should offer the user
higher speed and better quality communication capabilities than a typical
switched telephone line. Virtual private networks are, therefore, lines
used by individuals within a company or some other form of network using this
form to telecommute between home and the office. See telecommuting.
WAN – Wide-area
Network (Pronounced wan; rhymes with van).
A collection of computers connected (or networked)
to each other over a geographic area. Wide-area networks usually require special
arrangements with telephone companies because data is transmitted among
locations (called sites) across
telephone lines. Compare to local-area
network (LAN).
ZIP (zip files)
A widely used disk compression format
associated with PKWARE Inc.’s PKZIP (for compressing files) and PKUNZIP (for
decompressing files). The word “zip” and “zipped” are slang for a
compressed file; “unzip” and “unzipped” refer to decompressed files.
After a file is compressed, it is usually given the .ZIP file extension. Compare
to self-extracting file. Compare to UNZIP.