| A3D |
Provides a psuedo surround sound
from just two speakers. Found on many soundcards, as it is popular
with gameplaying software. |
| A4 |
The standard paper size in Europe, A4 is
11.75 inches by 8.5 inches. |
| A-law |
A digital audio encoding system used for
telephony. |
| A-B Roll |
Video editing using two video tape players
feeding a single tape recording device, usually fading one track
up while fading down the other track. |
| AC |
Alternating Current describes the power supply
available from the mains wall outlet. In the UK, the voltage is
230v, varying at a rate of 50Hz (50 cycles per second). In the US, the
voltage is 110v varying at 60HZ. |
| Accelerator Card |
An accelerator card is a video card whose chipset is
optimised for a certain type of application, such as 3D accelerators
or Windows. accelerators. |
| Access Time |
A disk or memory chip's access time is the time taken
to retrieve a single piece of data. |
| Access Provider |
An Access Provider is an ISP that provides access to
the internet but no additional features such as email. |
| ACK |
ACK is a data signal that acknowledges receipt of a
message. It may be the ASCII code 06. |
| ACPI |
The Advanced Configuration and Power Interface controls
power management and also IRQ Steering. |
| Acrobat |
Acrobat is a software application for publishing portable
PDF documents. |
| Acronyms |
Commonly-used abbreviations of terms, such that they
make up a new pronouncable word. Examples are GUI, RAM and ROM. |
| Acronyms, mail |
The shorthand found in many mail messages, such as
BTW (by the way) and FWIW (for what its worth). |
| Active Matrix Display |
An LCD panel that has three switching circuits for
each screen pixel. |
| Active video lines |
The number of lines that are visible on the monitor
screen. |
| Active Partition |
The Active Partition on a hard disk is the partition
from which the PC will attempt to boot. |
| ActiveX |
A comprehensive set of set of controls developed by
Microsoft for web browsing. |
| Active Window |
In a GUI, the Active Window is the window which has
the focus. |
| A/D Converter |
Circuitry on the sound card that converts speech and
music inputs into digital files. |
| Ad impressions |
A measure of how often a web page that contains an
advert is downloaded. |
| Adaptive Compression |
A compression system that can change its settings during
the compression process, to maximise the compression ratio. |
| Additive Colour |
The method of colour used in light-based devices, based
on addition of colour of three wavelengths: red, green and blue.
Compare Subtractive colour. |
| Address Bus |
The Address Bus is a bus on the motherboard that is
used by the CPU to select the memory or IO devices to access. |
| Address, IP |
Each machine on the Internet has an individual four-byte
IP address that is used to identify and allow communication with
the machine. |
| Address, Domain Name |
A machine's Domain Name Address is a textual name that
is used to represent the machine's actual IP address on the Internet,
for example 'mybusiness.co.uk'. |
| Address, email |
An email address consists of a username, the '@' character,
and the domain name of the machine on which the username's mailbox
is located. For example 'fred@mybusiness.co.uk'. |
| ADPCM |
Adaptive Differential Pulse Code Modulation is a method
of reducing audio files sizes by only saving the difference between
each sample. |
| ADSL |
Asymmetric Digital Subscriber Line is a high-speed
consumer data line whose download speed is considerably higher
than its upload speed. |
| ADSR |
Attack, Decay, Sustain, Release. Describes the four
stages in the envelope of a synthesised sound. |
| After Effects |
A software application from Adobe, providing a range
of motion graphic and visual effects for video, multimedia and
web applications. |
| AGC |
Automatic Gain Control is a system whereby high volume
levels are reduced before being output to avoid causing damage
to speakers. Also used to level out extremes on video signals. |
| AGP |
The Advanced Graphics Port is the fast slot on modern
motherboards, designed for connecting a graphics card. |
| AI |
Artificial Intelligence is the creation of software
that reasons and interacts like a human being. |
| AIFF |
Audio Interchange File Format is a type of sound file
that can contain both audio samples and MIDI sound. |
| Algorithm |
An algorithm is simply a well-defined logical method.
In computer programming, it refers specifically to the set of
program steps used to solve a particular problem (e.g. calculating
a date or moving a screen object). |
| Alias |
A name used to replace another name. Often used to
provide short alternatives to long e-mail addresses. Also used
to describe a rogue value in a multimedia file that distorts a
graphic image or audio clip. |
| Alignment |
The correct spacing, vertically and/or horizontally.
Applied to monitor constructiona and to displayed text. |
| Alpha Channel |
In images and graphics, the Alpha Channel is used to
describe the level of transparency of a pixel. |
| Alpha testing |
Alpha testing is the first stage of software testing, and is performed
in-house by the software developers. |
| Alphanumeric |
Alphanumerics are the set of characters that includes the alphabet (either
upper or lower case, or both) and the numbers zero to nine. |
| ALT key |
A key on the keyboard that is used to access 'alternative' control options.
It is normally used in conjunction with at least one other key. |
| ALU |
The Arithmetic & Logic Unit is the circuitry inside a
processor chip that carries out simple arithmetic tasks (e.g. addition,
subtraction, multiplication) and logic tasks (e.g. comparing values) |
| Ambient sound |
The background level of sound in a studio or recording location. |
| AMI |
American Megatrends, Inc. are a company whose most well-known computer
product is a range of BIOS chips. |
| Ampersand |
The '&' character, usually meaning 'and'. It is also used in some programming languages to join two items (such as words). |
| Amplitude Modulation |
A method of transferring data by means of a wave. The amplitude (height) of
the wave at any point determines whether it represents a 'one' or a 'zero'. |
| Analog |
Analog data has an infinite number of different levels, from sources such as mikes and analog videocameras. These can be stored or analog tapes. For storage and transfer in computer systems, the range has to be compressed into a set of digital values. |
| Analogue drive |
The monitor screen is driven by a voltage that can range through every possible small variation between fully on and fully off.. |
| Animation |
Similar to video, except that the content of the moving
picture is created from a sequence of artifically-created images rather than from a real-world recording. |
| Animation path |
An animation path is a line or curve along which any element moves during
the course of the animation. |
| Animated GIF |
A simple form of animation is to display consecutive graphic images, and that
is how an animated GIF works. |
| Anonymous FTP |
Many FTP sites are open to the public, and a user can log in anonymously,
normally giving an email address as a password. |
| ANSI |
The American National Standards Institute. This is a standards body, and the
name is often used to refer to their most widely used standard, which is a
display method allowing colour and special effects in a basic text screen. ANSsI also set the standards for programming languages, communication protocols, etc. |
| Anti-Aliasing |
Anti-aliasing is the removal or de-accentuation of unwanted pixellation in
raster (i.e. bitmap) graphics. This smooths out the jagged edges on images. |
| Anti-virus programs |
Anti-virus software is used to detect computer viruses, and disinfect them
where possible. It normally consists of a virus guard and a virus scanner. |
| Apache |
A public domain Internet server package, now the world's most popular web server software. |
| Aperture |
The hole in the front of the camera that lets the light through. It can be a fixed or a variable value. |
| Aperture Grille |
The Aperture Grille is like the shadow mask tube, except that the holes are vertical slots rather than round. It is used with Trinitron monitors. |
| Appendix |
A section at the end of a document/presentation that provides additional information. |
API |
The Applications Programming Interface is a piece of software that links the
application software to a specific hardware device (e.g. the graphics card). |
| Applet |
An Applet is a small program which is used by full-scale applications, most
commonly Java applets used in an HTML document. |
| Application software |
Application software is any package that is created to perform a specific function,
such as word processing or DTP. |
| Arabic numerals |
The normal presentation of numbers (i.e. 1,2,3) compared to Roman numerals (i.e. I, II, III, IV ). |
Archie |
An early method of finding files on the Internet. |
| Architecture |
A system's architecture describes the structure and operation of the core components
such as the buses, CPU and memory. The Von Neumann model is the most common. |
| Archive |
An Archive is an area of storage used to keep backups. Now commonly used to decribe files that have been compressed (e.g. .ZIP or .ARC files) |
| ARPAnet |
The Advanced Research Projects Agency Network is a network
of US research establishments. provided the basis for the current
Internet. |
| Artificial Intelligence |
An AI is a form of program that simulates human knowledge, for example being able to
diagnose illness or plot a travel route. |
| Ascending letters |
Those alphabetic characters that have strokes that rise above the height of the main body (e.g. b, d, h ). |
| ASCII |
The American Standard Code for Information Interchange is the method used to represent
the character set within a seven-bit value. |
| ASF |
The Active Streaming Format was developed by Microsoft to carry multimedia in real-time over the Internet. See 'streaming'. |
| ASK |
Amplitude Shift Keying is a method of data transmission that uses changes in signal amplitude to represent data. |
| ASIC chip |
An Application Specific Integrated Circuit is any chip
that has been developed for a special defined purpose (as opposed to a
general purpose chip) |
| ASP |
Active Server Pages describes the software used to interface Internet users to web sites' databases. |
| ASP |
Application Service Providers are web sites that store applications packages on their servers. They then 'rent' out the use of the software to users on a 'pay as you use' basis. Users are saved from purchasing an expensive package and paying for continual upgrades. |
| Aspect Ratio |
The ratio of the monitor screen's width to its height. A ratio of 4:3 is used with standard monitors and TV screens, while a 16:9 ratio is used with widescreen systems. |
| ASPI |
The Advanced SCSI Programming Interface is the 'open'
standard used to connect SCSI devices such as disk drives and CD-ROM
drives to the computer. |
| Assemble Editing |
A video editing process using a video source (e.g. camcorder) and recording device (e.g. VCR). Video clips are individually transferred from the source device to the recording device. The sequence of clips is built up in the order controlled by the user, allowing clips to be ignored, shortened or have their order altered. |
| Assembler |
A programming language that requires knowledge of the inner workings of the CPU. Produces very compact and very fast programs. |
| Associations |
See 'File Associations'. |
| Asterisk |
The * character that is used as a multiplication command in a spreadsheet formula. It is also used as a wildcard in some DOS and Windows commands. |
| Asynchronous |
A transmission method that allows data to be sent at irregular intervals, and a variety of speeds. Compare Synchronous. |
| Asymmetrical compression |
The file's encoding process is longer and more resource intensive than the decoding process. |
| AT Commands |
Modem commands developed by Hayes (a major modem manufacturer) and adopted by most other manufacturers. |
| AT Keyboard connector |
The 5-pin DIN plugs used to connect keyboards on older computers. Now replaced by PS/2 connections. |
| AT model computers |
The 16-bit computer standard originated with the 80286 CPU. |
| AT Power Supply |
Used with older motherboards, it uses two separate
connector cables. |
| ATA |
AT Attachment is is the specification for IDE disk
drive interfaces |
| ATAPI |
The AT Attachment Packet Interface is the method that
the disk controller uses to handle up to four IDE devices (disk
drives, CD-ROm drives, ZIP drives, etc). |
| ATM |
Asynchronous Transfer Mode is the method of sending
data over networks as a series of packets that are reassembled at
the receiving end. |
| Attachment |
Sending another file, such an image, video clip, spreadsheet,
etc, along with an e-mail. |
| Attribute |
Describes the characteristics of an object. For example,
a file has attributes that contain the file's size, whether it is
read-only or hidden, and so on. |
| ATX Motherboards |
A modern motherboard that uses a power supply with
a single connecting cable. |
| Audio dub |
Placing a new sound track on a video sequence. This
may be an addition to a clip that had no original audio (such an
an animation) or may be replacing an original sound track (such
as providing a commentary in another language). |
| Audio Mixer |
A hardware device, or software program, that allows
a number of audio sources (such as mikes, CD tracks and audiocassette
clips) to have their relative volumes altered. |
| Audio/Visual |
Contains content that can both be viewed and heard. |
| Audit |
A comprehensive examination of a computer system, checking
the main components (a hardware audit) or checking the software
installed on the system (a software audit). |
| Audit trail |
A record of the activities performed on a database,
useful for accountancy purposes or for repairing entry errors. |
| AUI |
The Attachment Unit Interface is the 15-pin connector
used to attach a computer to a local area network. |
| AUP |
An Acceptable Use Policy is a statement governing the
use of a system. Commonly used by Internet service providers to
limit use/abuse of the server. |
| Auto detection |
The BIOS chip detects the hard drive settings every
time the computer is booted up. |
| Autoexec.bat |
A batch file that runs when the computer is first booted
up into MSDOS. It contains commands to configure the computer. |
| Autoplay, CD |
A system that allows Windows to detect the insertion
of a CD disk and to run the program on the disk. |
| Availability |
The proportion of time that the computer
system can be used for productive activity, expressed as a percentage. |
| Avatars |
Animated characters that are selected by users to represent
them in web activities such as online games and chat rooms. |
| AVI |
'Audio Video Interleave' was developed by Microsoft
and is a main format for PC video clips |
| AZERTY keyboard |
A keyboard whose first line of keys begins with the
characters AZERTY instead of the usual QWERTY characters. Found
in some Euopean countries. |
