Jargon Buster A

A - B - C -D - E - F - G - H- I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

AC-3 - AKA Dolby Digital
AC-3, also known as Dolby Digital, is a perceptual digital audio coding technique that reduces the amount of data needed to produce high-quality sound. Perceptual digital audio coding takes advantage of the fact that the human ear screens out a certain amount of sound that is perceived as noise. Reducing, eliminating, or masking this noise significantly reduces the amount of data that needs to be provided. Dolby Laboratories developed two other perceptual coding systems, AC-1 and AC-2. Building upon Dolby's two previous coding systems, AC-3 was the first coding system designed specifically for multichannel digital audio. AC-3 is the sound format for digital television (DTV), digital versatile discs (DVDs), high definition television (HDTV), and digital cable and satellite transmissions. AC-3 is a 5.1 format, which means that it provides five full-bandwidth channels, front left, front right, center, surround left, and surround right. A low-frequency effect (LFE) channel is included for the sound needed for special effects and action sequences in movies. The LFE channel is one-tenth of the bandwidth of the other channels and is sometimes erroneously called the subwoofer channel. AC-3 also has a downmixing feature that ensures compatibility with devices that do not support the 5.1 format.

Access Point
In a wireless local area network (WLAN), an access point is a station that transmits and receives data (sometimes referred to as a transceiver). An access point connects users to other users within the network and also can serve as the point of interconnection between the WLAN and a fixed wire network. Each access point can serve multiple users within a defined network area; as people move beyond the range of one access point, they are automatically handed over to the next one. A small WLAN may only require a single access point; the number required increases as a function of the number of network users and the physical size of the network.

ACPI
Advanced Configuration and Power Interface
A power management specification that far surpasses its predecessor, APM, by providing support for hot swap-pable devices and better control of power modes.

Acrobat
Acrobat is a program from Adobe that lets you capture a document and then view it in its original format and appearance. Acrobat is ideal for making documents or brochures that were designed for the print medium viewable electronically and capable of being shared with others on the Internet. To view an Acrobat document, which is called a Portable Document Format (PDF) file, you need Acrobat Reader. The Reader is free and can be downloaded from Adobe. You can use it as a standalone reader or as a plug-in in a Web browser. Acrobat is actually a set of products. The latest version includes a "toolkit" that lets you scan in or otherwise capture documents created with Word, Pagemaker, and other desktop publishing products. The resulting PDF files can then be available for viewing either directly with the Reader or they can be viewed as embedded files within the browser.

Ad-Hoc Network
An ad-hoc (or "spontaneous") network is a local area network or other small network, especially one with wireless or temporary plug-in connections, in which some of the network devices are part of the network only for the duration of a communications session or, in the case of mobile or portable devices, while in some close proximity to the rest of the network. In Latin, ad hoc literally means "for this," further meaning "for this purpose only," and thus usually temporary. The term has been applied to future office or home networks in which new devices can be quickly added, using, for example, the proposed Bluetooth technology in which devices communicate with the computer and perhaps other devices using wireless transmission.

ADSL - Asymmetric Digital Subscriber Line
A technology for transmitting digital information at high bandwidths on existing phone lines. Unlike regular dialup phone service, ADSL provides a continously-available connection. ADSL is asymmetric in that it uses most of the channel to transmit downstream to the user and only a small part to receive information from the user. ADSL simultaneously accommodates analog (voice) information on the same line. ADSL is generally offered at downstream data rates from 512 Kbps to about 6 Mbps.

Adware
Generically, adware (spelled all lower case) is any software application in which advertising banners are displayed while the program is running. The authors of these applications include additional code that delivers the ads, which can be viewed through pop-up windows or through a bar that appears on a computer screen. The justification for adware is that it helps recover programming development cost and helps to hold down the cost for the user. Adware has been criticized because it usually includes code that tracks a user's personal information and passes it on to third parties, without the user's authorization or knowledge. This practice has been dubbed spyware and has prompted an outcry from computer security and privacy advocates, including the Electronic Privacy Information Center.

AF - Anisotropic Filtering
Anisotropic filtering is used to address a specific kind of texture artifact that occurs when a 3D surface is sloped relative to the view camera.

AGP - Accelerated Graphics Port
A 32/64-bit expansion slot designed by Intel specifically for video that runs at 66 MHz and yields a throughput of at least 254 MBps. Later versions (2X, 4X, 8X) give substantially higher throughput. AIX (Advanced Interactive Executive) IBM's version of UNIX, which runs on 386 or better PCs.

Alphanumeric
In computers designed for English language users, alphanumeric (sometimes seen as alphameric) characters are those comprised by the combined set of the 26 alphabetic characters, A to Z, and the 10 Arabic numerals, 0 to 9. In some usages, the alphanumeric character set may include both upper and lower case letters, punctuation marks, and symbols (such as @, &, and *, for example). For languages other than English, alphanumeric characters include letter variations such as é and ç. For some computer usages, such as file naming, alphanumeric characters are strictly limited to the 26 alphabetic characters and 10 numerals; however, for other usages, such as programming, other keyboard symbols are sometimes permitted.

ALU - Arithmetic Logic Unit
An internal part of the processor which is used for all mathematical and logical operations, the basic operations of an ALU include adding and multiplying binary values as well as performing logical operations such as AND, OR and XOR. The algorithms for performing these mathematical and logical operations are hard coded (stored permanently) within the ALU.

AMD - Advanced Micro Devices
Founded in 1969 and based in Sunnyvale, California, AMD designs and produces innovative microprocessors, Flash memory devices, and low-power processor solutions for the computer, communications, and consumer electronics industries.

AMI - American Megatrends Inc
Major producer of BIOS software for mother-boards, as well as many other computer-related components and software.

AMPS - Amperes
A quantity of charge is measured in units called coulombs, and the word "ampere" means the same thing as "one coulomb of charge flowing per second." If we were talking about water, then Coulombs would be like gallons, and amperage would be like gallons-per-second of water flow.

AMR (Audio/Modem Riser)
AMR (Audio/Modem Riser) is a specification developed by Intel for packaging the analog I/O audio functions of modem circuitry together with a codec chip (which converts back and forth from analog to digital) on a small board that plugs directly into a computer's motherboard. The small board is called a riser because it rises above the motherboard rather than laying flatly on it. Having this circuitry on a riser means that it doesn't have to be part of the motherboard itself. Because getting certification for the manufacture of a new motherboard design is a lengthy process, removing this function from the motherboard provides more flexibility for manufacturers and allows advances in audio modem design to be implemented more easily. Another specification, MDC (Mobile Daughter Card) is the equivalent of AMR but for use in mobile computers.

Anamorphic
A method of enhancing DVD discs to minimise the letterbox effect.

Antenna
An antenna is a specialized transducer that converts radio-frequency (RF) fields into alternating current (AC) or vice-versa. There are two basic types: the receiving antenna, which intercepts RF energy and delivers AC to electronic equipment, and the transmitting antenna, which is fed with AC from electronic equipment and generates an RF field. In computer and Internet wireless applications, the most common type of antenna is the dish antenna, used for satellite communications. Dish antennas are generally practical only at microwave frequencies (above approximately 3 GHz). The dish consists of a paraboloidal or spherical reflector with an active element at its focus. When used for receiving, the dish collects RF from a distant source and focuses it at the active element. When used for transmitting, the active element radiates RF that is collimated by the reflector for delivery in a specific direction. At frequencies below 3 GHz, many different types of antennas are used. The simplest is a length of wire, connected at one end to a transmitter or receiver. More often, the radiating/receiving element is placed at a distance from the transmitter or receiver, and AC is delivered to or from the antenna by means of an RF transmission line, also called a feed line or feeder

Antivirus Software
Antivirus (or "anti-virus") software is a class of program that searches your hard drive and floppy disks for any known or potential viruses. The market for this kind of program has expanded because of Internet growth and the increasing use of the Internet by businesses concerned about protecting their computer assets.

Aperture
Adjustable opening in the lens of a camcorder used to regulate how much light reaches the CCD image sensor.

API - Application Programming Interface
A software definition that describes operating system calls for application software; conventions defining how a service is invoked, direct X for example.

APM - Advanced Power Management
The BIOS routines that enable the CPU to turn on and off selected peripherals.

Apple Computer
Apple Computer, Inc. is a prominent hardware and software company best known for its Macintosh series of personal computers. Introduced in 1984, the Macintosh was the first widely sold personal computer with a graphical user interface (GUI). That feature and others -- such as an improved floppy drive design and a low-cost hard drive that made data retrieval faster and more reliable -- helped Apple cultivate a reputation for innovation, which the company still enjoys today. The Apple headquarters are located in Cupertino, CA, at 1-5 Infinite Loop. Apple borrowed the name for the circular road around their office buildings from programming, where an infinite loop is the term for a code sequence lacking a functional exit. Apple was founded by Steven Jobs and Stephen Wozniak. Jobs and Wozniak had been friends in high school and in 1975 were members of The Homebrew Computer Club, a now-legendary group where electronics enthusiasts met to discuss the Altair 8800 (the only personal computer available at the time) and other technical topics. Wozniak designed his own microcomputer and offered his plans to Hewlett-Packard, where he was working as an engineering intern. After HP turned him down, Wozniak joined forces with Jobs to manufacture personal computers in Job's garage. That endeavor started out as a shoestring operation, but quickly became successful. The pair introduced a relatively modern-looking computer in a plastic case in 1977 and incorporated as Apple Computer that same year. By 1980 the company had grown to include over 1000 employees.

ASCII - American Standard Code for Information Interchange
American Standard Code for Information Interchange: A widely used character encoding system first used in 1963. It uses a 7 bit code to represent characters with numbers (0 to 127), there are also ASCII extensions in use which utilise 8 bit codes to represent international characters in addition to the standard ASCII scheme.

ASP - Active Server Pages
Active Server Pages: We are refering to ASP in the context of dynamic web pages, ASP can also refer to Application Service Provider. When in the context of internet web sites ASP refers to a specification similar to that of CGI, ASP technology allows the site developer to create dynamic web pages through the use of ActiveX. ASP pages are used for numerous tasks including form handling, database connectivity, even putting a date and time on a page. Jscript or VB Script are the most common scripting languages used with ASP pages.

ATA - Advanced Technology Attachment
A type of hard drive and controller. ATA was 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. Includes HDD speeds I.E ATA/100 /33/ 66 the numeric string denotes the drive rate in MBs per second.

ATAPI - Advanced Technology Attachment Packet Interface
A series of standards that enable mass stor-age devices other than hard drives to use the IDE/ATA controllers. Extremely popular with CD-ROM drives and removable media drives.

ATX - Advanced Technology eXtended
The modern-day shape and layout of PC motherboards. It improves on the previous standard, the Baby AT form factor, by rotating the orientation of the board 90 degrees. This allows for a more efficient design, with disk drive cable connectors nearer to the drive bays and the CPU closer to the power supply and cooling fan.

AV - Audio Visual
An AV computer is capable of input and/or output of audio (sound) and video (picture) to and from external hardware, such as video cameras, VCRs, computer projection devices, and large screen monitors.

AVI - Audio Video Interleaved
A multimedia file type, the audio and video elements are interleaved in alternate segments within the AVI file. This has become a very popular format on the Internet for video distribution due to the fast download times and reasonable quality reproduction.

AVI file
An AVI (Audio Video Interleaved) file is a sound and motion picture file that conforms to the Microsoft Windows Resource Interchange File Format (RIFF) specification. AVI files (which end with an .avi extension) require a special player that may be included with your Web browser or may require downloading.