Codec
Short for compressor/decompress,
a codec is any technology for compressing
and decompressing data. Codec’s can
be implemented in software, hardware, or
a combination of both. Some popular
codec’s for computer video include
MPEG, Indeo and Cinepak.
Cold
Boot
A cold reboot (also
known as a hard reboot) is when power to a
computer is cycled (turned
on and off) or a special reset signal to the
processor is triggered (from a front panel
switch of some sort). This restarts the computer
without first performing the usual shut-down
procedure. (With many operating systems, especially
those with disc caches, after a hard reboot
the system may well be in an "unclean" state,
and require that checks and repairs to on-disc
file system structures be performed before
normal operation can begin.)
Collision
The situation that occurs
when two or more devices attempt to send a
signal along the
same channel
at the same time. The result of a collision
is generally a garbled message. All computer networks
require some sort of mechanism to either prevent
collisions altogether or to recover from collisions
when they do occur.
COM
Stands
for Component Object Module. In DOS systems,
the name of a serial communications
port. DOS supports
four serial ports: COM1, COM2, COM3, and COM4.
However, most software uses system
interrupts to access the
serial ports, and there are only two IRQ lines
reserved.
Command Line
Commands you type to run an application.
You can type commands at an MS-DOS
prompt or in the Run
dialog box in the Program Manager of Windows.
Interfaces in which you type commands
rather than choose them
from a menu are often called command line
interfaces. MS-DOS has a command line
interface while the Macintosh
does not.
Compiler
This is
an application that converts a programming language
into a machine language
program.
Config.SYS
The configuration file for DOS systems.
Whenever a DOS computer boots up, it
reads the CONFIG.SYS
file (if it exists) and executes any
commands in it. The most common commands
are BUFFERS=
and FILES=,
which enable you to specify the buffer
size and the number of files that can
be open
simultaneously.
Contrast Ratio
Is a method of measuring a dynamic range.
The higher the contrast ratio, the
more detailed the image
will be. Blacks will be blacker, whites
will be whiter,
and particularly text on the image
will be more vivid.
Controller
A device that controls the transfer
of data from a computer to a peripheral
device and
vice versa.
Controllers must be designed to communicate
with the computer's expansion bus.
There
are three standard
bus architectures for PCs -- the
AT bus, PCI (Peripheral Component Interconnect),
and SCSI.
Conventional
Memory
On DOS systems, conventional memory
refers to the portion of memory
that is available
to standard
DOS programs. DOS systems have
an address space of 1MB
(megabyte), but the top 384K
(called high memory) is reserved for system
use. This
leaves 640K of
conventional memory. Everything
above
1MB is either extended or
expanded memory.
CPE
Customer Premises Equipment.
Used to describe the PC and/or
other equipment
that the
customer may
want to connect to the cable
modem.
CPM (Cost
Per Thousand)
The practice of calculating a
cost per 1000 ad displays. It
is used
by programs
that
pay on an
impression
basis -- with the CPM rate being
the amount you earn for every
1000 times
an advertisement
is displayed.
CPU
Central Processing Unit. In a
microcomputer, a processor on
an IC chip (called
a microprocessor) that serves
as the heart of the computer.
It interprets and
carries out instructions, performs
numeric computations, and controls
the peripherals
connected to it. Often
the entire system unit is called
the CPU.
CSS
Stands for Cascading Style Sheets.
Daisy Chain
A hardware configuration in which devices
are connected one to another in a series.
The SCSI interface, for example, supports
a daisy chain of up to 7 devices.
Data
Anything that is recorded or used for processing.
The stuff that transfers between computers
needed a name -- data seemed good.
Data Bus
A group of parallel conductors (circuit traces)
found on the motherboard that is used by
the CPU to send and receive data from all
the devices in the computer. Also called
the external data bus.
Data Conversion
The translation of data from one format to
another. Often when data are moved from one
system to another, some form of data conversion
is required to convert the data to a format
the receiving system can interpret. Sometimes
it is necessary to have an intermediate format.
Database
Anything that accepts data is a database.
A pile of newspapers is a database. A computer
database has the ability to manipulate that
data. It is possible to attach applications
to that database to search the contents.
Data Rate
Speed that information moves from one item
to another. This is usually in the form of
bits.
Daughter Card
A printed circuit board that plugs into another
circuit board (usually the motherboard).
A daughter card is similar to an expansion
board, but it accesses the motherboard components
(memory and CPU) directly instead of sending
data through the slower expansion bus.
DDR
Stands for "Double Data Rate." It
is an advanced version of SDRAM, a type of
computer memory. DDR-SDRAM, sometimes called "SDRAM
II," can transfer data twice as fast
as regular SDRAM chips. This is because DDR
memory can send and receive signals twice
per clock cycle. The efficient operation
of DDR-SDRAM makes the memory great for notebook
computers since it uses up less power.
DDS
Stands for Direct Digital Signal. A network
whose infrastructure equipment is completely
digital. All signals on such a network are
transmitted digitally and there is no need
for analog-to-digital converters.
Decoder
A circuit or device that restores a coded
signal to its original form based on knowledge
of the process used to code the signal.
Decryption
Decryption is the process of converting encrypted
data back into its original form, so it can
be understood.
Dedicated Line
This is a phone line meant specifically for
one thing, like being attached to a computer.
Demodulation
This is the process of converting analog
information (like over phone lines) into
digital information (like in a computer).
See "Modem" for more.
DHCP
Dynamic Host Configuration Protocol. This
protocol provides a mechanism for allocating
IP addresses dynamically so that addresses
can be reused. Often used for managing the
IP addresses of all the cable modems in a
cable plant and the PC's connected to the
cable modems.
DHTML
Stands for Dynamic HTML.
Dial-Up Line
This is a telephone line that is connected
to a server. When it is called, tones are
exchanged between the server and the devise
calling in order to attach.
Dial-Up Networking
A component in Windows 95 that enables you
to connect your computer to a network via
a modem. If your computer is not connected
to a LAN and you want to connect to the Internet,
you need to configure Dial-Up Networking
(DUN) to dial a Point of Presence (POP) and
log into your Internet Service Provider (ISP).
Digital
A system that defines data in a discrete,
non-fluctuating (i.e., non-analogue), numerical
method. Similar to a binary system.
DIP
Acronym for dual in-line package, a type
of chip housed in a rectangular casing with
two rows of connecting pins on either side.
DLL
Dynamic Link Library. A file of functions,
compiled, linked, and saved separately from
the processes that use them. Functions in
DLLs can be used by more than one running
process. The operating system maps the DLLs
into the process's address space when the
process is started up or while it is running.
Dynamic link libraries are stored in files
with the .DLL file extension.
DMA
Hardware devices attached to PCs (ranging
from keyboards to sound cards) can be designed
to send their instructions to and from main
memory in one of two ways. The default is
to ask the CPU to do the work. The more efficient
way is to allocate one of the PC's DMA channels
to send instructions directly to memory.
This leaves the CPU free to do more important
things.
DNS
Domain Name Service is the system used on
the Internet for mapping names (called domain
names) to the actual numerical addresses
of machines on the Internet (IP addresses).
Every computer on the Internet has its own
number.
DOCSIS
Data Over Cable Service Interface Specification.
The dominating cable modem standard. Defines
technical specifications for both cable modem
and CMTS.
Dongle
A device that attaches to a computer to control
access to a particular application. Dongles
provide the most effective means of copy
protection. Typically, the dongle attaches
to a PC's parallel port.
DOS
Stands for Disc Operating System. It is a
generic term for the many programs that accept
commands to trip applications to run. The
most popular is MS-DOS (MS stands for Microsoft).
Downstream
The data flowing from the Cable Modem Termination
System to the cable modem.
Downstream frequency
The frequency used for transmitting data
from the Cable Modem Termination System to
the cable modem. Normally in the 42/65-850
MHz range depending on the actual cable plant
capabilities.
Domain
A group of computers and devices on a network
that are administered as a unit with common
rules and procedures. Within the Internet,
domains are defined by the IP address. All
devices sharing a common part of the IP address
are said to be in the same domain.
Domain Name
A name that identifies one or more IP addresses.
Every domain name has a suffix that indicates
which top-level (TLD) domain it belongs to.
Because the Internet is based on IP addresses,
not domain names, every Web server require
a Domain Name System (DNS) server to translate
domain names into IP addresses.
DRAM
DRAM (dynamic random access memory) is most
commonly used type of memory in computers.
A bank of DRAM memory usually forms the computer's
main memory. It is called Dynamic because
it needs to be refreshed.
Driver
A program that controls a device. Every device,
whether it is a printer, disk drive, or
keyboard, must have a driver program. Many
drivers, such as the keyboard driver, come
with the operating system. For other devices,
you may need to load a new driver when
you connect the device to your computer.
DSP (Digital Signal Processor)
DSP chips are widely used in sound cards,
fax machines, modems, cellular phones, high-capacity
hard disks and digital TVs. The first DSP
chip used in a commercial product was believed
to be from Texas Instruments, which was used
in its very popular Speak & Spell game
in the late 1970s. DSP chips are used in
sound cards for recording and playback and
speech synthesis.
DVD
Short for digital versatile disc or digital
video disc, a new type of CD-ROM that holds
a minimum of 4.7GB (gigabytes), enough for
a full-length movie.
Dynamic URL
A URL that results from the search of a database-driven
Web site or the URL of a Web site that runs
a script.
EBCDIC
Extended Binary Coded Decimal Interchange
Code. It is also called the Extended ASCII
Code, as it adds an eighth digit to the
normal seven-digit code.
ECC Memory
Error Checking and Correction. A method of
detecting and correcting system memory errors
by adding additional bits and using a special
algorithm.
EDO Memory
Short for Extended Data Output Dynamic Random
Access Memory, a type of DRAM that is faster
than conventional DRAM. Unlike conventional
DRAM which can only access one block of data
at a time, EDO RAM can start fetching the
next block of memory at the same time that
it sends the previous block to the CPU.
E-Mail
Stands for Electronic Mail. This is a system
of relaying messages across the Internet,
from one Internet user to another.
Emulation
Refers to the ability of a program or device
to imitate another program or device.
Encryption
Encryption is the process of converting data
into "unreadable code" is so that
unauthorized people cannot understand the
content. Encryption may be used to make stored
data private (e.g., data that is stored on
a potentially vulnerable hard disk), or to
allow a nosecone communications channel to
serve as a private communications channel.
Engine (as in "Search Engine"):
This is the working part of a database or
application.
EPROM
Acronym for erasable programmable read-only
memory, and pronounced ee-prom, EPROM is
a special type of memory that retains its
contents until it is exposed to ultraviolet
light.
Error Rate
In many cases, it may be acceptable if an
input device generates a certain number of
errors. This is often referred to as the
error rate and the acceptable level will
vary according to the input device being
used and the business application.
ESD
Stands for Electro Static Discharge and is
defined as a sudden flow of electricity between
two objects at different electrical potentials.
ESD is a primary cause of integrated circuit
damage or failure.
Ethernet
A networking system that enables high speed
data communication over coaxial cables.
The Ethernet network system supports TCP/IP,
AppleTalk, Novell Netware, and other network
protocols.
Executable File
A file in a format that the computer can directly execute. Unlike source files,
executable files cannot be read by humans.
Expanded Memory
Also known as EMS (Expanded Memory Specification), expanded memory is a technique
for utilizing more than 1MB (megabyte) of main memory in DOS -based computers.
Expansion Bus
A group of control lines that provide a buffered interface to devices located
either on the system board or on cards that are plugged into expansion connectors.
Common expansion buses included on the system board are USB, PC Card, and PCI.
Extended Memory
Memory above and beyond the standard 1MB (megabyte) of main memory that DOS
supports. Extended memory is only available in PCs with an Intel 80286 or later
microprocessor.
External Modem
A modem that resides in a self-contained box outside the computer system.
Extranet
An extranet is a private network that uses the Internet protocols and the public
tele-communication system to share a business’s information , data or
operations with external suppliers, vendors or customers.
Fault Tolerance
The ability of a system to respond gracefully
to an unexpected hardware or software failure.
There are many levels of fault tolerance,
the lowest being the ability to continue
operation in the event of a power failure.
FAQ
Stands for Frequently Asked Questions. An
FAQ is a file or document where a moderator
or administrator will post commonly asked
questions and their answers.
Fax Modem
A device you can attach to a personal computer
that enables you to transmit and receive
electronic documents as faxes.
Fibre
Optic
An alternative to copper wire for transmitting
information. In Fibre optics, pulses of
light representing binary data are flashed
along
a flexible glass Fibre.
File Sharing
This is the most important feature of the
Internet. This is a method of allowing one
server to give the same file to many different
end users.
Firmware
Software (programs or data) that has been
written onto read-only memory (ROM). Firmware
is a combination of software and hardware.
ROMs, PROMs and EPROMs that have data or
programs recorded on them are firmware.
Freeware
This is a shortened version of Free Software.
Programmers offer their work without wanting
pay in return.
FSB
Stands for Front Side Bus, which denotes
the speed at which your processor interacts
with the components on the motherboard.
FTP
Stands for File Transfer Protocol.
Gateway
As in Common Gateway Interface (CGI). It
is a piece of software that allows two
items to communicate with each other. They
are used to make connections between computers
and systems inside that computer.
General Protection Fault
GPF, short for General Protection Fault,
is a computer condition that causes a Windows
application to crash.
GIF
Pronounced "jif." Stands for Graphical
Interchange Format. It is an image format
created by CompuServe.
Gigabyte
2 to the 30th power (1,073,741,824) bytes.
One gigabyte is equal to 1,024 megabytes.
Gigabyte is often abbreviated as G or GB.
GIGO
It's an acronym that stands for Garbage In,
Garbage Out.
Glyph
A graphic symbol whose appearance conveys
information; for example, the vertical and
horizontal arrows on cursor keys that indicate
the directions in which they control cursor
movement.
Gopher
A method of distributing information by computers
that has waned in popularity to ftp. Most
gopher files contain only text information
with few images, audio, or video components.
Files can be downloaded with a similar protocol
like ftp.
GUI -
Graphical User Interface
A program interface that takes advantage
of the computer's graphics capabilities to
make the program easier to use. Well-designed
graphical user interfaces can free the user
from learning complex command languages.
Half-Duplex
Refers to the transmission of data in just
one direction at a time. For example, a walkie-talkie
is a half-duplex device because only one
party can talk at a time. In contrast, a
telephone is a full-duplex device because
both parties can talk simultaneously.
Handshaking
The process by which two devices initiate
communications. Handshaking begins when
one device sends a message to another device
indicating that it wants to establish a
communications channel.
Hard Boot
A hard reboot (also known as a cold reboot)
is when power to a computer is cycled (turned
on and off) or a special reset signal to
the processor is triggered (from a front
panel switch of some sort).
Hardware
These are the physical items including your
computer and floppy discs.
Heat Sink
A component designed to lower the temperature
of an electronic device by dissipating heat
into the surrounding air. All modern CPUs
require a heat sink. Some also require a
fan.
Helper Application
This is an application your browser uses
to manipulate a downloaded program.
HFC
Hybrid fibre-coaxial (cable network). Older
CATV systems were provisioned using only
coaxial cable. Modern systems use fibre transport
from the headend to an optical node located
in the neighborhood to reduce system noise.
High Memory Area
In DOS -based systems, the high memory area
refers to the first 64K of extended memory.
Host
A computer on a network that provides services
to other computers on the network. Unless
you have your own server, you need a hosting
company who provides a server or computer
that is connected to the internet and makes
your web pages available to the rest of the
internet.
HTML
Hyper Text Mark-up Language. It is a collection
of structuring and formatting tags used to
create Web pages.
HTTP
Stands for HyperText Transport Protocol.
Common protocol used to communicate between
World Wide Web Servers.
Hub
A common connection point for devices in
a network. Hubs are commonly used to connect
segments of a LAN. A hub contains multiple
ports. When a packet arrives at one port,
it is copied to the other ports so that all
segments of the LAN can see all packets.
Hybrid
A device or system combining two types of
mechanisms, circuits, or design approaches,
each of which could of itself accomplish
the total function but in a different and
usually less effective manner. A hybrid
computer combines digital and analog computers
into one functioning system.
Hypertext
This is a mark-up language that allows for
non-linear transfers of data. The method
allows your computer to provide the computational
power rather than attaching to a mainframe
and waiting for it to do the work for you.
IBM
Stands for International Business Machines
ICMP
(Internet Control Message Protocol) A message
control and error-reporting protocol between
a host server and a gateway to the Internet.
Icon:
A small video display that acts as an activation
link when clicked on.
IDE
(Integrated Development Environment) A programming
environment integrated into an application.
IMAP
Internet Message Access Protocol
IMAP is gradually replacing POP as the
main protocol used by email clients in
communicating
with email servers.
Integrated Circuit
Another name for a chip, an IC is a small
electronic device made out of a semiconductor
material.
Interface
This is any type of point where two different
things come together. Most often, the term
is used to describe the programs between
you and your computer like Windows, OS/2
and others. What you see on the screen
is the interface between you and what your
computer
is doing.
Internal Modem
A modem that resides on an expansion board
that plugs into a computer. In contrast,
an external modem is a box that attaches
to a computer's COM port via cables.
Internet
The Internet is a super-network. It connects
many smaller networks together and allows
all the computers to exchange information
with each other. To accomplish this all
the computers on the Internet have to use
a common
set of rules for communication. Those rules
are called protocols, and the Internet
uses a set of protocols called TCP/IP (Transmission
Control Protocol/Internet Protocol). Many
people equate the World Wide Web with the
Internet. In fact, the Internet is like
the
highway, and the World Wide Web is like
a truck that uses that highway to get from
place to place.
Interrupt
A signal informing a program that an event
has occurred. When a program receives an
interrupt signal, it takes a specified
action (which can be to ignore the signal).
Interrupt
signals can cause a program to suspend
itself temporarily to service the interrupt.
Intranet
A private network for communications and
sharing of information that, like the Internet,
is based on TCP/IP but is accessible only
to authorized users within an organization.
An organization’s intranet is usually
protected from external access by a firewall.
See also: Extranet.
IS
Stands for Information System.
ISDN
Integrated Services Digital Network. ISDN
is a public global network capable of transmitting
voice, data and images at speeds up to 128K.
The digital technique can transport more signals
on the same telephone line than
the traditional analogue technique and enables
a range of new services.
ISP
Internet Service Provider, a company that
provides access to the Internet. For a monthly
fee, the service provider gives you a software
package, username, password and access phone
number. Equipped with a modem, you can then
log on to the Internet and browse the World
Wide Web and USENET, and send and receive
e-mail.
JAVA
Java is an object-oriented language similar
to C++, but simplified to eliminate language
features that cause common programming errors.
JavaScript
This is a language very close to Java that
allows for more interaction with the viewer.
It is much more forgiving than Java as doesn't
require its own window in which to work.
JPEG
Pronounced "J-Peg." Stands for
Joint Photographic Experts Group. It's an
image format that allows for compression
when stored.
Jumpers
A metal bridge that closes an electrical
circuit. Typically, a jumper consists of
a plastic plug that fits over a pair of protruding
pins. Jumpers are sometimes used to configure
expansion boards. By placing a jumper plug
over a different set of pins, you can change
a board's parameters.
Kbit/s
Stands for thousands of bits per second.
Kilobyte (KB)
This is about a thousand bytes of space.
In reality, it's two to the 10th power or
1,024 bytes.
KVM
Keyboard-Video-Mouse switch. A piece of hardware
that connects two or more computers to a
single keyboard, monitor and mouse.
LAN
A computer network that spans a relatively
small area. Most LANs are confined to a single
building or group of buildings. However,
one LAN can be connected to other LANs over
any distance via telephone lines and radio
waves. A system of LANs connected in this
way is called a wide area network (WAN).
LCD
Abbreviation of liquid crystal display, a
type of display used in digital watches
and many portable computers. LCD displays
utilize two sheets of polarizing material
with a liquid crystal solution between
them. LED:
Abbreviation of light emitting diode, an
electronic device that lights up when electricity
is passed through it. LEDs are usually red.
They are good for displaying images because
they can be relatively small, and they do
not burn out. However, they require more
power than LCDs.
Linux
A version of UNIX that runs on a variety
of hardware platforms including x86 PCs,
Alpha, PowerPC and IBM's product line. Linux
is open source software, which is freely
available. Linux has gained popularity with
Internet Service Providers as the Operating
System of choice for hosting Web servers.
Live Script
This is the former name of Java Script. There
are few updates between the two.
Login
To attach to a computer. It has also come
to represent your User ID command.
Login Script
This is the small text file
that is run by the server gateway to make
the attachment between it and your computer.
LVD
Low Voltage Differential. A differential
logic scheme using lower voltage levels
than HVD.
Mainframe
Mostly a mainframe is only a mainframe when
compared to a desktop computer. It's bigger
and much more powerful. Sometimes it's
called a server or CPU.
MBR
Short for Master Boot Record, a small program
that is executed when a computer boots up.
Typically, the MBR resides on the first sector
of the hard disk.
MCNS
Multimedia Cable Network System Partners
Ltd. The consortium behind the DOCSIS standard
for cable modems.
Megabyte (MB)
About a million bytes of space. Actually
its 2 raised to the 20th power or 1,048,576
bytes of space.
Memory
Internal storage areas in the computer. The
term memory identifies data storage that
comes in the form of chips, and the word
storage is used for memory that exists on
tapes or disks.
Microcomputer
A category of computer that is generally
used for personal computing, for small business
computing, and as a workstation attached
to large computers or to other small computers
on a network.
Microprocessor
A silicon chip that contains a CPU. In the
world of personal computers, the terms microprocessor
and CPU are used interchangeably. Microprocessors
also control the logic of almost all digital
devices, from clock radios to fuel-injection
systems for automobiles.
MIDI
Stands for Music Instrument Digital Interface.
It allows a computer to store and replay
a musical instrument's output.
Modem
This is a word created out of the beginning
letters of two other words: MOdulation and
DEModulation. The words mean the changing
of data from digital |