~E~
Easter egg~erase
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
Easter egg
n. A hidden feature of a computer program. It may be a hidden command, an animation, a humorous message, or a list of credits for the people who developed the program. In order to display an Easter egg, a user often must enter an obscure series of keystrokes.
EBCDIC
n. Acronym for Extended Binary Coded Decimal Interchange Code. An IBM code that uses 8 bits to represent 256 possible characters (compared with unextended ASCII's 7 bits and 128 characters). It is used primarily in IBM mainframes, whereas personal computers use ASCII. Compare ASCII.
e-bomb
n. Short for e-mail bomb. A technique used by some hackers in which a target is put on a large number of mailing lists so that network traffic and storage are tied up by e-mail sent by other mailing list subscribers to the lists' recipients.
ECC
See error-correcting code, error-correction coding.
echo1
n. In communications, a signal transmitted back to the sender that is distinct from the original signal. Network connections can be tested by sending an echo back to the main computer.
echo2
vb. To transmit a received signal back to the sender. Computer programs, such as MS-DOS and OS/2, can be commanded to echo input by displaying data on the screen as it is received from the keyboard. Data communications circuits may echo text back to the originating terminal to confirm that it has been received.
echo check
n. In communications, a method for verifying the accuracy of transmitted data by retransmitting it to the sender, which compares the echoed signal with the original.
EDI
n. Acronym for electronic data interchange. A set of standards for controlling the transfer of business documents, such as purchase orders and invoices, between computers. The goal of EDI is the elimination of paperwork and increased response time. For EDI to be effective, users must agree on certain standards for formatting and exchanging information, such as the X.400 protocol. See also CCITT X series, standard (definition 1).
edit
vb. 1. To make a change to an existing file or document. Changes to the existing document are saved in memory or in a temporary file but are not added to the document until the program is instructed to save them. Editing programs typically provide safeguards against inadvertent changes, such as by requesting confirmation before saving under an existing filename, by allowing the user to assign a password to a file, or by giving the option of setting the file to read-only status. 2. To run software that makes extensive, predictable changes to a file automatically, such as a linker or a filter for graphics.
editing keys
n. A set of keys on some keyboards that assist in editing. Located between the main keyboard and the numeric keypad, editing keys consist of three pairs: Insert and Delete, Home and End, and Page Up and Page Down.
edit key
n. In a software application, a predefined key or combination of keys that, when pressed, causes the application to enter edit mode.
edit mode
n. The mode of a program in which a user can make changes to a document, as by inserting or deleting data or text. Compare command mode.
editor
n. A program that creates files or makes changes to existing files. An editor is usually less powerful than a word processor, lacking the latter's capability for text formatting, such as use of italics. Text or full-screen editors allow the user to move through the document using direction arrows. In contrast, line editors require the user to indicate the line number on which text is to be edited. See also Edlin.
Edlin
n. An outdated line-by-line text editor used in MS-DOS through version 5. Its OS/2 counterpart is SSE. See also editor.
EDO DRAM
n. Acronym for extended data out dynamic random access memory. A type of memory that allows for faster read times than DRAM of comparable speed by allowing a new read cycle to begin while data is being read from a previous cycle. This allows for faster overall system performance. Compare dynamic RAM, EDO RAM.
EDO RAM
n. Acronym for extended data out random access memory. A type of dynamic RAM that keeps data available for the CPU while the next memory access is being initialized, resulting in increased speed. Pentium-class computers using Intel's Triton chip set are designed to take advantage of EDO RAM. See also central processing unit, dynamic RAM. Compare EDO DRAM.
edutainment
n. Multimedia content in software, on CD-ROM, or on a Web site that purports to educate the user as well as entertain. See also multimedia.
EEMS
n. Acronym for Enhanced Expanded Memory Specification. A superset of the original Expanded Memory Specification (EMS). Version 3.0 of EMS allowed only storage of data and supported 4-page frames. EEMS allowed up to 64 pages along with executable code to be stored in expanded memory. The features of EEMS were included in EMS version 4.0. See also EMS, page frame.
EEPROM
n. Acronym for electrically erasable programmable read-only memory. A type of EPROM that can be erased with an electrical signal. It is useful for stable storage for long periods without electricity while still allowing reprogramming. EEPROM contain less memory than RAM, take longer to reprogram, and can be reprogrammed only a limited number of times before wearing out. See also EPROM, ROM.
e-form
n. Short for electronic form. An online document that contains blank spaces for a user to fill in with requested information and that can be submitted through a network to the organization requesting the information. On the Web, e-forms are often coded in CGI and secured via encryption. See also CGI (definition 1).
EGA
n. Acronym for Enhanced Graphics Adapter. An IBM video display standard introduced in 1984. It emulates the Color/Graphics Adapter (CGA) and the Monochrome Display Adapter (MDA) and provides medium-resolution text and graphics. It was superseded by Video Graphics Display (VGA).
EISA
n. Acronym for Extended Industry Standard Architecture. A bus standard for the connection of add-on cards to a PC motherboard, such as video cards, internal modems, sound cards, drive controllers, and cards that support other peripherals. EISA was introduced in 1988 by a consortium of nine computer industry companies. The companies--AST Research, Compaq, Epson, Hewlett-Packard, NEC, Olivetti, Tandy, Wyse, and Zenith--were referred to collectively as "the Gang of Nine." EISA maintains compatibility with the earlier Industry Standard Architecture (ISA) but provides for additional features introduced by IBM in its Micro Channel Architecture bus standard. EISA has a 32-bit data path, and it uses connectors that can accept ISA cards. However, EISA cards are compatible only with EISA systems. EISA can operate at much higher frequencies than the ISA bus and provides much faster data throughput than ISA. See also ISA, Micro Channel Architecture.
electromagnetic radiation
n. The propagation of a magnetic field through space. Radio waves, light, and X rays are examples of electromagnetic radiation, all traveling at the speed of light.
electron gun
n. A device that produces an electron beam, typically found in television or computer monitors. See also CRT.
electronic commerce
n. Commercial activity that takes place by means of connected computers. Electronic commerce can occur between a user and a vendor through an online information service, the Internet, or a BBS, or between vendor and customer computers through electronic data interchange (EDI). Also called e-commerce. See also EDI.
electronic credit
n. A form of electronic commerce involving credit card transactions carried out over the Internet. Also called e-credit. See also electronic commerce.
Electronic Frontier Foundation
n. A public advocacy organization dedicated to the defense of civil liberties for computer users. The organization was founded in 1990 by Mitchell Kapor and John Perry Barlow as a response to U.S. Secret Service raids on hackers. Acronym: EFF.
electronic mail services
n. Services that allow users, administrators, or daemons to send, receive, and process e-mail. See also daemon.
electronic mall
n. A virtual collection of online businesses that affiliate with the intention of increasing the exposure of each business through the fellow businesses.
electronic publishing
n. A general term for distributing information via electronic media, such as communications networks or CD-ROM.
electronics
n. The branch of physics dealing with electrons, electronic devices, and electrical circuits.
electronic software distribution
n. A means of directly distributing software to users on line over the Internet. Electronic software distribution is analogous to direct-mail ordering. Acronym: ESD.
electronic storefront
n. A business that displays its merchandise on the Internet and has provisions for contact or online sales.
ellipsis
n. A set of three dots (...) used to convey incompleteness. In many windowing applications, selection of a command that is followed by an ellipsis will produce a submenu or a dialog box. In programming and software manuals, an ellipsis in a syntax line indicates the repetition of certain elements. See also dialog box, syntax.
e-mail1
or email or E-mail n. 1. The exchange of text messages and computer files over a communications network, such as a local area network or the Internet, usually between computers or terminals. 2. An electronic text message.
e-mail2
or email or E-mail vb. To send an e-mail message.
e-mail address
n. A string that identifies a user so that the user can receive Internet e-mail. An e-mail address typically consists of a name that identifies the user to the mail server, followed by an at sign (@) and the host name and domain name of the mail server. For example, if Anne E. Oldhacker has an account on the machine called baz at Foo Enterprises, she might have an e-mail address aeo@baz.foo.com, which would be pronounced "A E O at baz dot foo dot com."
e-mail filter
n. A feature in e-mail-reading software that automatically sorts incoming mail into different folders or mailboxes based on information contained in the message. For example, all incoming mail from a user's Uncle Joe might be placed in a folder labeled "Uncle Joe." Filters may also be used either to block or accept e-mail from designated sources.
embedded
adj. In software, pertaining to code or a command that is built into its carrier. For example, application programs insert embedded printing commands into a document to control printing and formatting. Low-level assembly language is embedded in higher-level languages, such as C, to provide more capabilities or better efficiency.
embedded hyperlink
n. A link to a resource that is embedded within text or is associated with an image or an image map. See also hyperlink, image map.
em dash
n. A punctuation mark (--) used to indicate a break or interruption in a sentence. It is named for the em, a typographical unit of measure that in some fonts equals the width of a capital M. Compare en dash, hyphen.
EMM
n. See Expanded Memory Manager.
e-money
or emoney n. Short for electronic money. A generic name for the exchange of money through the Internet. Also called cybercash, digicash, digital cash, e-cash.
emoticon
n. A string of text characters that, when viewed sideways, form a face expressing a particular emotion. An emoticon is often used in an e-mail message or newsgroup post as a comment on the text that precedes it. Common emoticons include :-) or :) (meaning "I'm smiling at the joke here"), ;-) ("I'm winking and grinning at the joke here"), :-( ("I'm sad about this"), :-7 ("I'm speaking with tongue in cheek"), :D or :-D (big smile; "I'm overjoyed"), and :-O (either a yawn of boredom or a mouth open in amazement). Compare emotag.
EMS
n. Acronym for Expanded Memory Specification. A technique for adding memory to PCs that allows for increasing memory beyond the Intel 80x86 microprocessor real-mode limit of 1 megabyte. In earlier versions, EMS bypassed this memory board limit with a number of 16-kilobyte banks of RAM that could be accessed by software. In later versions of Intel microprocessors, including the 80386 and 80486 models, EMS is converted from extended memory by software memory managers, such as EMM386 in MS-DOS 5. Now EMS is used mainly for older MS-DOS applications because Windows and other applications running in protected mode on 80386 and higher microprocessors are free of the 1-MB limit. Also called LIM EMS. See also expanded memory, protected mode. Compare conventional memory, extended memory.
em space
n. A typographical unit of measure that is equal in width to the point size of a particular font. For many fonts, this is equal to the width of a capital M, from which the em space takes its name. Compare en space, fixed space, thin space.
emulate
vb. For a hardware or software system to behave in the same manner as another hardware or software system. In a network, microcomputers often emulate mainframes or terminals so that two machines can communicate.
emulation
n. The process of a computer, device, or program imitating the function of another computer, device, or program.
enable
vb. To activate or turn on. Compare disable.
encapsulate
vb. To treat a collection of structured information as a whole without affecting or taking notice of its internal structure. In communications, a message or packet constructed according to one protocol, such as a TCP/IP packet, may be taken with its formatting data as an undifferentiated stream of bits that is then broken up and packaged according to a lower-level protocol (for example, as ATM packets) to be sent over a particular network; at the destination, the lower-level packets are assembled, re-creating the message as formatted for the encapsulated protocol. In object-oriented programming, the implementation details of a class are encapsulated in a separate file whose contents do not need to be known by a programmer using that class. See also ATM (definition 1), object-oriented programming, TCP/IP.
Encapsulated PostScript
n. See EPS.
encode
vb. 1. In data security, to encrypt. See also encryption. 2. In programming, to put something into code, which frequently involves changing the form--for example, changing a decimal number to binary-coded form. See also binary-coded decimal, EBCDIC.
encryption
n. The process of encoding data to prevent unauthorized access, especially during transmission. Encryption is usually based on a key that is essential for decoding. The U.S. National Bureau of Standards created a complex encryption standard, Data Encryption Standard (DES), which provides almost unlimited ways to encrypt documents. See also DES.
encryption key
n. A sequence of data that is used to encrypt other data and that, consequently, must be used for the data's decryption. See also decryption, encryption.
endless loop
n. See infinite loop.
end-of-file
n. A code placed by a program after the last byte of a file to tell the computer's operating system that no additional data follows. In ASCII, end-of-file is represented by the decimal value 26 (hexadecimal 1A) or the Ctrl-Z control character. Acronym: EOF.
End-User License Agreement
n. A legal agreement between a software manufacturer and the software's purchaser with regard to terms of distribution, resale, and restricted use. Acronym: EULA.
Energy Star
n. A symbol affixed to systems and components that denotes lower power-consumption design. Energy Star is the name of an Environmental Protection Agency program that encourages PC manufacturers to build systems that are energy efficient. Requirements dictate that systems or monitors be capable of automatically entering a lower power-consumption state or "sleep state" while the unit is inactive, where the low-power state is defined as 30 watts or less. Systems and monitors that comply with these guidelines are marked with an Energy Star sticker.
engine
n. A processor or portion of a program that determines how the program manages and manipulates data. The term engine is most often used in relation to a specific program; for example, a database engine contains the tools for manipulating a database. Compare back-end processor, front-end processor.
Enhanced Graphics Display
n. A PC video display capable of producing graphic images with resolutions ranging from 320 × 200 to 640 × 400 pixels, in color or in black and white. Resolution and color depth depend on the vertical and horizontal scanning frequencies of the display, the capabilities of the video display controller card, and available video RAM.
Enhanced IDE
n. Short for Enhanced Integrated Drive Electronics. An extension of the IDE standard, Enhanced IDE is a hardware interface standard for disk drive designs that house control circuits in the drives themselves. It allows for standardized interfaces to the system bus while providing for advanced features, such as burst data transfer and direct data access. Enhanced IDE accommodates drives as large as 8.4 gigabytes (IDE supports up to 528 megabytes). It supports the ATA-2 interface, which permits transfer rates up to 13.3 megabytes per second (IDE permits up to 3.3 megabytes per second), and the ATAPI interface, which connects drives for CD-ROMs, optical discs and tapes, and multiple channels. Most PCs have Enhanced IDE drives, which are cheaper than SCSI drives and provide much of the same functionality. See also IDE, SCSI. Acronym: EIDE.
enhanced keyboard
n. An IBM 101/102-key keyboard that replaced the PC and AT keyboards. It features 12 function keys across the top (rather than 10 on the left side), extra Control and Alt keys, and a bank of cursor and editing keys between the main keyboard and number pad. It is similar to the Apple Extended Keyboard.
enhanced parallel port
n. A connection port for peripheral devices, most often used for printers, external disk drives, or tape drives. Enhanced parallel ports utilize high-speed circuits for faster data throughput. Data and communications control lines are wired in parallel; each data line corresponds to 1 data bit. Data is transferred across all lines in sync. See also input/output port. Acronym: EPP.
enhanced serial port
n. A connection port for peripheral devices, commonly used for mice and external modems. Enhanced serial ports utilize 16550-type or newer high-speed UART circuits for faster data throughput. Data is transferred as a sequence of bits and bytes on a pair of lines, either synchronously (data flows in one direction only) or asynchronously (data flows each way in turn). See also input/output port, UART. Acronym: ESP.
ENIAC
n. An 1800-square-foot, 30-ton computer containing 17,468 vacuum tubes and 6,000 manual switches. Developed between 1942 and 1946 for the U.S. Army by J. Presper Eckert and John Mauchly at the University of Pennsylvania, ENIAC is considered to have been the first truly electronic computer. It remained in operation until 1955.
enlarge
vb. In Microsoft Windows and other graphical user interfaces, to increase the size of a window. See also maximize. Compare minimize, reduce.
E notation
n. See floating-point notation.
Enter key
n. The key that is used at the end of a line or command to instruct the computer to process the command or text. In word processing programs, the Enter key is used at the end of a paragraph. Also called Return key.
enterprise computing
n. In a large enterprise such as a corporation, the use of computers in a network or series of interconnected networks that generally encompass a variety of different platforms, operating systems, protocols, and network architectures. Also called enterprise networking.
enterprise network
n. In a large enterprise such as a corporation, the network (or interconnected networks) of computer systems owned by the enterprise, which fills the enterprise's various computing needs. This network can span diverse geographical locations and usually encompasses a range of platforms, operating systems, protocols, and network architectures.
EOL
n. Acronym for end of line. A control (nonprinting) character that signals the end of a data line in a data file.
EOT
n. See end-of-transmission.
EPP IEEE standard
n. An IEEE standard relating to the Enhanced Parallel Port (EPP) protocol. This protocol was originally developed by Intel, Xircom, and Zenith Data Systems as a means to provide a high-performance parallel port link that would still be compatible with the standard parallel port. This protocol capability was implemented by Intel in the 386SL chip set (82360 I/O chip), prior to the establishment of the IEEE 1284 committee and the associated standards work. The EPP protocol offered many advantages to parallel port peripheral manufacturers and was quickly adopted by many as an optional data transfer method. A loose association of around 80 interested manufacturers was formed to develop and promote the EPP protocol. This association became the EPP Committee and was instrumental in helping to get this protocol adopted as one of the IEEE 1284 advanced modes. See also IEEE, parallel port, protocol.
EPROM
n. Acronym for erasable programmable read-only memory. A nonvolatile memory chip that is programmed after it is manufactured. EPROMs can be reprogrammed by removing the protective cover from the top of the chip and exposing the chip to ultraviolet light. Though EPROMS are more expensive than PROM chips, they can be more cost-effective if many changes are required. Also called reprogrammable read-only memory (RPROM). See also EEPROM, PROM, ROM.
EPS
n. Acronym for Encapsulated PostScript. A PostScript file format that can be used as an independent entity. The EPS image must be incorporated into the PostScript output of an application such as a desktop publisher. Many high-quality clip-art packages consist of such images. See also PostScript.
erase
vb. To remove data permanently from a storage medium. This is usually done by replacing existing data with zeros or meaningless text or, in magnetic media, by disturbing the magnetic particles' physical arrangement, either with the erase head or with a large magnet. Erase differs from delete in that delete merely tells the computer that data or a file is no longer needed; the data remains stored and is recoverable until the operating system reuses the space containing the deleted file. Erase, on the other hand, removes data permanently. See also erase head. Compare delete.
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