ARP-through-AVI
A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time
ARP
n. Acronym for Address Resolution Protocol. A TCP/IP protocol for determining the hardware address (or physical address) of a node on a local area network connected to the Internet, when only the IP address (or logical address) is known. An ARP request is sent to the network, and the node that has the IP address responds with its hardware address. Although ARP technically refers only to finding the hardware address, and RARP (for Reversed ARP) refers to the reverse procedure, ARP is commonly used for both senses. See also IP address, TCP/IP.
ARPANET
n. A large wide area network created in the 1960s by the U.S. Department of Defense Advanced Research Projects Agency (ARPA, renamed DARPA in the 1970s) for the free exchange of information between universities and research organizations, although the military also used this network for communications. In the 1980s MILNET, a separate network, was spun off from ARPANET for use by the military. ARPANET was the network from which the Internet evolved. See also Internet, MILNET.
ARP request
n. Short for Address Resolution Protocol request. An ARP packet containing the Internet address of a host computer. The receiving computer responds with or passes along the corresponding Ethernet address. See also ARP, Ethernet, IP address, packet.
arrow key
n. Any of four keys labeled with arrows pointing up, down, left, and right, used to move the cursor vertically or horizontally on the display screen or, in some programs, to extend the highlight.
artificial intelligence
n. The branch of computer science concerned with enabling computers to simulate such aspects of human intelligence as speech recognition, deduction, inference, creative response, the ability to learn from experience, and the ability to make inferences given incomplete information. Two common areas of artificial-intelligence research are expert systems and natural-language processing. See also expert system, natural-language processing. Acronym: AI.
artificial life
n. The study of computer systems that simulate some aspects of the behavior of living organisms. Artificial life includes systems in which programs intended to perform some particular task compete for survival and reproduction based on their performance; the offspring can combine pieces of code and undergo random variations, and the programs so modified compete in turn, until an optimal solution is found.
ascender
n. The portion of a lowercase letter that extends above the main body (x-height) of the letter. See also baseline, x-height. Compare descender.
ascending order
n. The arrangement of a sequence of items from lowest to highest, such as from 1 to 10 or from A to Z. The rules for determining ascending order in a particular application can sometimes be very complicated: capital letters before lowercase letters, extended ASCII characters in ASCII order, and so on.
ascending sort
n. A sort that results in the arrangement of items in ascending order. See also alphanumeric sort, ascending order. Compare descending sort.
ascii
n. In an FTP client program, the command that instructs the FTP server to send or receive files as ASCII text. See also ASCII, FTP client. Compare binary2.
ASCII
n. Acronym for American Standard Code for Information Interchange. A coding scheme using 7 or 8 bits that assigns numeric values to up to 256 characters, including letters, numerals, punctuation marks, control characters, and other symbols. ASCII was developed in 1968 to standardize data transmission among disparate hardware and software systems and is built into most minicomputers and all personal computers. See also ASCII file, character, character code, control character, extended ASCII. Compare EBCDIC.
ASCII file
n. A document file in ASCII format, containing characters, spaces, punctuation, carriage returns, and sometimes tabs and an end-of-file marker, but no formatting information. Also called ASCII file, text file, text-only file. See also ASCII, text file. Compare binary file.
aspect ratio
n. In computer displays and graphics, the ratio of the width of an image or image area to its height. An aspect ratio of 2:1, for example, indicates that the image is twice as wide as it is high. The aspect ratio is an important factor in maintaining correct proportions when an image is printed, rescaled, or incorporated into another document.
assembler
n. A program that converts assembly language programs, which are understandable by humans, into executable machine language. See also assemble, assembly language, assembly listing, compiler (definition 2), machine code.
assembly language
n. A low-level programming language using abbreviations or mnemonic codes in which each statement corresponds to a single machine instruction. An assembly language is translated to machine language by the assembler and is specific to a given processor. Advantages of using an assembly language include increased execution speed and direct programmer interaction with system hardware. See also assembler, compiler, high- level language, low-level language, machine code.
associate
vb. To inform the operating system that a particular filename extension is linked to a specific application. When a file is opened that has an extension associated with a given application, the operating system automatically starts the application and loads the file.
asterisk
n. 1. The character (*) used in applications and programming languages to signify multiplication. 2. In Windows, MS-DOS, OS/2, and other operating systems, a wildcard character that can be used in place of other characters, as in *.*, which represents any combination of filename and extension. See also question mark, star-dot-star, wildcard character. 3. In the C and C++ programming languages, the character used to dereference a pointer to a class or structure. See also dereference, pointer (definition 1).
asynchronous device
n. A device whose internal operations are not synchronized with the timing of any other part of the system.
asynchronous operation
n. An operation that proceeds independently of any timing mechanism, such as a clock. For example, two modems communicating asynchronously rely upon each sending the other start and stop signals in order to pace the exchange of information. Compare synchronous operation.
asynchronous procedure call
n. A function call that executes separately from an executing program when a set of enabling conditions exist. After the conditions have been met, the operating system's kernel issues a software interrupt and directs the executing program to execute the call. See also function call. Acronym: APC.
asynchronous transmission
n. In modem communication, a form of data transmission in which data is sent intermittently, one character at a time, rather than in a steady stream with characters separated by fixed time intervals. Asynchronous transmission relies on the use of a start bit and stop bit(s), in addition to the bits representing the character (and an optional parity bit), to distinguish separate characters.
ATA
n. Acronym for Advanced Technology Attachment. ANSI group X3T10's official name for the disk drive interface standard commonly known as Integrated Drive Electronics (IDE). Also called AT Attachment.
ATA/IDE hard disk drive
n. IDE (Integrated Drive Electronics--or numerous other interpretations) and ATA (AT Attachment) are one and the same thing: a disk drive implementation designed to integrate the controller onto the drive itself, thereby reducing interface costs and making firmware implementations easier.
ATAPI
n. The interface used by the IBM PC AT system for accessing CD-ROM devices.
AT bus
n. The electric pathway used by IBM AT and compatible computers to connect the motherboard and peripheral devices. The AT bus supports 16 bits of data, whereas the original PC bus supports only 8 bits. Also called expansion bus. See also EISA, ISA, Micro Channel Architecture.
ATDP
n. Acronym for Attention Dial Pulse, a command that initiates pulse (as opposed to touch-tone) dialing in Hayes and Hayes-compatible modems. Compare ATDT.
ATDT
n. Acronym for Attention Dial Tone, a command that initiates touch-tone (as opposed to pulse) dialing in Hayes and Hayes-compatible modems. Compare ATDP.
ATM
n. Acronym for Asynchronous Transfer Mode. A network technology capable of transmitting data, voice, video, and frame relay traffic in real time. Data, including frame relay data, is broken into packets containing 53 bytes each, which are switched between any two nodes in the system at rates ranging from 1.5 Mbps to 622 Mbps. ATM is defined in the broadband ISDN protocol at the levels corresponding to levels 1 and 2 of the ISO/OSI model. It is currently used in local area networks involving workstations and personal computers, but it is expected to be adopted by the telephone companies, which will be able to charge customers for the data they transmit rather than for their connect time. See also broadband, ISDN, ISO/OSI model. See Adobe Type Manager.
ATM Forum
n. Forum created in 1991 and including more than 750 companies related to communications and computing, as well as government agencies and research groups. The forum aims to promote Asynchronous Transfer Mode for data communication. See also ATM (definition 1).
attach
vb. To include an external document as part of an e-mail message, using MIME or some other encoding application. Most modern e-mail clients have the ability to attach documents, as well as to decode attached documents that are received.
attached document
n. An ASCII text file or a binary file, such as a document created in a word processing system, that is included with an e-mail message as an attachment. The file is not part of the actual e-mail message, and it is generally encoded using uuencoding, MIME, or BinHex. Most e-mail programs automatically encode an attached document for transmission with a message. The recipient of the message must have an e-mail program capable of decoding the attached document or use a separate utility to decode it in order to read the document. See also ASCII, binary file, BinHex, MIME, uuencode.
attached processor
n. A secondary processor attached to a computer system, such as a keyboard or video subsystem processor.
attenuation
n. The weakening of a transmitted signal, such as the distortion of a digital signal or the reduction in amplitude of an electrical signal, as it travels farther from its source. Attenuation is usually measured in decibels and is sometimes desirable, as when signal strength is reduced electronically, for example, by a radio volume control, to prevent overloading.
attribute
n. 1. In a database record, the name or structure of a field. For example, the files LASTNAME, FIRSTNAME, and PHONE would be attributes of each record in a PHONELIST database. The size of a field or the type of information it contains would also be attributes of a database record. 2. In screen displays, an element of additional information stored with each character in the video buffer of a video adapter running in character mode. Such attributes control the background and foreground colors of the character, underlining, and blinking. 3. In markup languages such as SGML and HTML, a name-value pair within a tagged element that modifies certain features of that element. See also HTML, SGML.
audio
adj. Relating to frequencies within the range of perception by the human ear--from about 15 to 20,000 hertz (cycles per second). See also audio response, synthesizer.
audio card
n. An expansion card that converts analog audio signals from a microphone, audio tape, or other source to digital form that can be stored as a computer audio file, and converts computer audio files to electrical signals that can be played through a speaker. Output sounds can be routed through speakers or headphones. Input can be entered through a microphone connected to the computer. Most audio cards support MIDI. Audio cards enable sounds to be heard from CD-ROMs and other storage media or over the Internet. Also called audio board, sound board, sound card. See also MIDI.
audiocast
n. The transmission of an audio signal using IP protocols. See also IP.
audio compression
n. A method of reducing the overall loudness of an audio signal. This is accomplished by limiting the amount of apparent distortion when the signal is played back through a speaker or transmitted through a communications link.
audiovisual
adj. Relating to or being any material that uses a combination of sight and sound to present information.
audit trail
n. In reference to computing, a means of tracing all activities affecting a piece of information, such as a data record, from the time it is entered into a system to the time it is removed. An audit trail makes it possible to document, for example, who made changes to a particular record and when.
authentication
n. In a multiuser or network operating system, the process by which the system validates a user's logon information. A user's name and password are compared against an authorized list, and if the system detects a match, access is granted to the extent specified in the permission list for that user. See also logon, password, permission, user account, user name.
authorization
n. In reference to computing, especially remote computers on a network, the right granted an individual to use the system and the data stored on it. Authorization is typically set up by a system administrator and verified by the computer based on some form of user identification, such as a code number or password. Also called access privileges, permission. See also network, system administrator.
AutoCorrect
n. A function in Microsoft Word for Windows that automatically corrects errors and makes other substitutions as soon as a user types text. For example, AutoCorrect can be set up to fix misspellings, such as teh for the, or to change "straight" quotation marks to "smart" quotation marks. The user can select which AutoCorrect features to enable. See also smart quotes.
auto dial
n. A feature enabling a modem to open a telephone line and initiate a call by transmitting a stored telephone number as a series of pulses or tones.
AUTOEXEC.BAT
n. A special-purpose batch file (set of commands) that is automatically carried out by the MS-DOS operating system when the computer is started or restarted. Created by the user or (in later versions of MS-DOS) by the operating system at system installation, the file contains basic startup commands that help configure the system to installed devices and to the user's preferences.
AutoPlay
n. A feature in Windows 95 that allows it to automatically operate a CD-ROM. When a CD is inserted into a CD-ROM drive, Windows 95 looks for a file called AUTORUN.INF on the CD. If the file is found, Windows 95 will open it and carry out its instructions, which are usually to set up an application from the CD-ROM on the computer's hard disk or to start the application once it has been installed. If an audio CD is inserted into the drive, Windows 95 will automatically launch the CD Player application and play it.
autopolling
n. The process of periodically determining the status of each device in a set so that the active program can process the events generated by each device, such as whether a mouse button was pressed or whether new data is available at a serial port. This can be contrasted with event-driven processing, in which the operating system alerts a program or routine to the occurrence of an event by means of an interrupt or message rather than having to check each device in turn. Also called polling. Compare event-driven processing, interrupt-driven processing.
autorestart
n. A process or system feature that can automatically restart the system after the occurrence of certain types of errors or a power system failure.
autosave
n. A program feature that automatically saves an open file to a disk or other medium at defined intervals or after a certain number of keystrokes to ensure that changes to a document are periodically saved.
autosizing
n. The ability of a monitor to accept signals at one resolution and display the image at a different resolution. A monitor capable of autosizing maintains the aspect ratio of an image but enlarges or reduces the image to fit in the space available. See also monitor, resolution.
AUX
n. The logical device name for auxiliary device; a name reserved by the MS-DOS operating system for the standard auxiliary device. AUX usually refers to a system's first serial port, also known as COM1.
A/UX
n. A version of the multi-user, multitasking UNIX operating system provided by Apple Computer for various Macintosh computers and based on the AT&T System V, release 2.2 of UNIX with some enhancements. A/UX incorporates a number of Apple features, including support for the Macintosh Toolbox, so that applications can provide users with the graphics-based interface characteristic of that computer. See also System V.
availability
n. In processing, the accessibility of a computer system or resource, such as a printer, in terms of usage or of the percentage of the total amount of time the device is needed.
avatar
n. In virtual-reality environments such as certain types of Internet chat rooms, a graphical representation of a user. An avatar typically is a generic picture or animation of a human of either gender, a photograph or caricature of the user, a picture or animation of an animal, or an object chosen by the user to depict his or her virtual-reality "identity." See superuser.
AVI
n. Acronym for Audio Video Interleaved. A Windows multimedia file format for sound and moving pictures that uses the Microsoft RIFF (Resource Interchange File Format) specification.
A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time