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Glossary Of Computer Terms
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
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i486DX: n. An Intel microprocessor introduced in 1989. In addition to the
features of the 80386 (32-bit registers, 32-bit data bus, and 32-bit addressing), the i486DX has a built-in cache
controller, a built-in floating-point coprocessor, provisions for multiprocessing, and a pipelined execution scheme.
Also called 486, 80486. See also pipelining (definition 1).
i486DX2: n. An Intel microprocessor introduced in 1992 as an upgrade to certain
i486DX processors. The i486DX2 processes data and instructions at twice the system clock frequency. The increased
operating speed leads to the generation of much more heat than in an i486DX, so a heat sink is often installed
on the chip. Also called 486DX, 80486. See also heat sink, i486DX, microprocessor. Compare OverDrive.
i486SL: n. A low-power-consumption version of Intel's i486DX microprocessor
designed primarily for laptop computers. The i486SL operates at a voltage of 3.3 volts rather than 5 volts, can
shadow memory, and has a System Management Mode (SMM) in which the microprocessor can slow or halt some system
components when the system is not performing CPU-intensive tasks, thus prolonging battery life. See also i486DX,
i486SX: n. An Intel microprocessor introduced in 1991 as a lower-cost alternative
to the i486DX. It runs at slower clock speeds and has no floating-point processor. Also called 486, 80486. See
also 80386DX, 80386SX. Compare i486DX.
IAB: See Internet Architecture Board.
I-beam: n. A mouse cursor used by many applications, such as word processors,
when in text-editing mode. The I-beam cursor indicates sections of the document where text can be inserted, deleted,
changed, or moved. The cursor is named for its I shape. Also called I-beam pointer. See also cursor (definition
IBM AT: n. A class of personal computers introduced in 1984 and conforming
to IBM's PC/AT (Advanced Technology) specification. The first AT was based on the Intel 80286 processor and dramatically
outperformed its predecessor, the XT, in speed. See also 80286.
IBM PC: n. Short for IBM Personal Computer. A class of personal computers introduced
in 1981 and conforming to IBM's PC specification. The first PC was based on the Intel 8088 processor. For a number
of years, the IBM PC was the de facto standard in the computing industry for PCs, and clones, or PCs that conformed
to the IBM specification, have been called PC-compatible. See also PC-compatible.
ICMP: n. Acronym for Internet Control Message Protocol. A network-layer (ISO/OSI
level 3) Internet protocol that provides error correction and other information relevant to IP packet processing.
For example, it can let the IP software on one machine inform another machine about an unreachable destination.
See also communications protocol, IP, ISO/OSI model, packet (definition 1).
icon: n. A small image displayed on the screen to represent an object that
can be manipulated by the user. By serving as visual mnemonics and allowing the user to control certain computer
actions without having to remember commands or type them at the keyboard, icons are a significant factor in the
user-friendliness of graphical user interfaces. See also graphical user interface.
iconic interface: n. A user interface that is based on icons rather than on
typed commands. See also graphical user interface, icon.
IDE: n. Acronym for Integrated Device Electronics. A type of disk-drive interface
in which the controller electronics reside on the drive itself, eliminating the need for a separate adapter card.
The IDE interface is compatible with the controller used by IBM in the PC/AT computer but offers advantages such
as look-ahead caching. See integrated development environment.
idle: adj. 1. Operational but not in use. 2. Waiting for a command.
IE: n. Acronym for information engineering. A methodology for developing and
maintaining information-processing systems, including computer systems and networks, within an organization. See
IEEE: n. Acronym for Institute of Electrical and Electronics Engineers. An
organization of engineering and electronics professionals notable for developing standards for hardware and software.
IEEE 488: n. The electrical definition of the General-Purpose Interface Bus
(GPIB), specifying the data and control lines and the voltage and current levels for the bus. See also General-Purpose
IEEE 696/S-100: n. The electrical definition of the S-100 bus, used in early
personal computer systems that used microprocessors such as the 8080, Z-80, and 6800. The S-100 bus, based on the
architecture of the Altair 8800, was extremely popular with early computer enthusiasts because it permitted a wide
range of expansion boards. See also Altair 8800, S-100 bus.
IEEE 802 standards: n. A set of standards developed by the IEEE to define methods
of access and control on local area networks. The IEEE 802 standards correspond to the physical and data-link layers
of the ISO Open Systems Interconnection model, but they divide the data-link layer into two sublayers. The logical
link control (LLC) sublayer applies to all IEEE 802 standards and covers station-to-station connections, generation
of message frames, and error control. The media access control (MAC) sublayer, dealing with network access and
collision detection, differs from one IEEE 802 standard to another: IEEE 802.3 is used for bus networks that use
CSMA/CD, both broadband and baseband, and the baseband version is based on the Ethernet standard. IEEE 802.4 is
used for bus networks that use token passing, and IEEE 802.5 is used for ring networks that use token passing (token
ring networks). In addition, IEEE 802.6 is an emerging standard for metropolitan area networks, which transmit
data, voice, and video over distances of more than five kilometers. See also bus network, ISO/OSI model, ring network,
token passing, token ring network.
IETF: n. Acronym for Internet Engineering Task Force. The organization that
is charged with studying technical problems facing the Internet and proposing solutions to the IAB. The IETF is
managed by the IESG. See also Internet Engineering Steering Group.
IFF: n. Acronym for Interchange File Format. See .iff.
IGES: n. See Initial Graphics Exchange Specification.
IIS: See Internet Information Server.
illegal: adj. Not allowed, or leading to invalid results. For example, an illegal
character in a word processing program would be one that the program cannot recognize; an illegal operation might
be impossible for a program or system because of built-in constraints. Compare invalid.
image: n. 1. A stored description of a graphic picture, either as a set of
brightness and color values of pixels or as a set of instructions for reproducing the picture. See also bit map,
pixel map. 2. A duplicate, copy, or representation of all or part of a hard or floppy disk, a section of memory
or hard drive, a file, a program, or data. For example, a RAM disk can hold an image of all or part of a disk in
main memory; a virtual RAM program can create an image of some portion of the computer's main memory on disk. See
also RAM disk.
image color matching: n. The process of image output correction to match the
same colors as were scanned or input.
image editor: n. An application program that allows users to modify the appearance
of a bitmapped image, such as scanned photos, by using filters and other functions. Creation of new images is generally
accomplished in a paint or drawing program. See also bitmapped graphics, filter (definition 4), paint program.
image map: n. An image that contains more than one hyperlink on a Web page.
Clicking on different parts of the image links the user to other resources on another part of the Web page, a different
Web page, or a file. Often an image map, which can be a photograph, drawing, or a composite of several different
drawings or photographs, is used as a map to the resources found on a particular Web site. Image maps are created
with CGI scripts. Also called clickable maps. See also CGI script, hyperlink, Web page.
imaging: n. The processes involved in the capture, storage, display, and printing
of graphical images.
IMAP4: n. Acronym for Internet Message Access Protocol 4. The latest version
of IMAP, a method for an e-mail program to gain access to e-mail and bulletin-board messages stored on a mail server.
Unlike POP, IMAP allows a user to retrieve messages efficiently from more than one computer. See also POP3, Post
IMHO: Acronym for in my humble opinion. IMHO, used in e-mail and in online
forums, flags a statement that the writer wants to present as a personal opinion rather than as a statement of
IMO: Acronym for in my opinion. A shorthand phrase used often in e-mail and
Internet news and discussion groups to indicate an author's admission that a statement he or she has just made
is not strictly a fact.
inactive window: n. In an environment capable of displaying multiple on-screen
windows, any window other than the one currently being used for work. An inactive window can be partially or entirely
hidden behind another window, and it remains inactive until the user selects it. Compare active window.
in-band signaling: n. Transmission within the voice or data-handling frequencies
of a communication channel.
Inbox: n. In many e-mail applications, the default mailbox where the program
stores incoming messages. See also e-mail, mailbox. Compare Outbox.
indent1: n. 1. Displacement of the left or right edge of a block of text in
relation to the margin or to other blocks of text. 2. Displacement of the beginning of the first line of a paragraph
relative to the other lines in the paragraph. Compare hanging indent.
indent2: vb. To displace the left or right edge of a text item, such as a block
or a line, relative to the margin or to another text item.
index1: n. 1. A listing of keywords and associated data that point to the location
of more comprehensive information, such as files and records on a disk or record keys in a database. 2. In programming,
a scalar value that allows direct access into a multi-element data structure such as an array without the need
for a sequential search through the collection of elements. See also array, element (definition 1), hash, list.
index2: vb. 1. In data storage and retrieval, to create and use a list or table
that contains reference information pointing to stored data. 2. In a database, to find data by using keys such
as words or field names to locate records. 3. In indexed file storage, to find files stored on disk by using an
index of file locations (addresses). 4. In programming and information processing, to locate information stored
in a table by adding an offset amount, called the index, to the base address of the table.
indexed search: n. A search for an item of data that uses an index to reduce
the amount of time required.
INET: n. 1. Short for Internet. 2. An annual conference held by the Internet
infobahn: n. The Internet. Infobahn is a mixture of the terms information and
Autobahn, a German highway known for the high speeds at which drivers can legally travel. Also called Information
Highway, Information Superhighway, Net.
information: n. The meaning of data as it is intended to be interpreted by
people. Data consists of facts, which become information when they are seen in context and convey meaning to people.
Computers process data without any understanding of what the data represents.
information explosion: n. 1. The current period in human history, in which
the possession and dissemination of information has supplanted mechanization or industrialization as a driving
force in society. 2. The rapid growth in the amount of information available today. Also called information revolution.
Information Highway or information highway: n. See Information Superhighway
information processing: n. The acquisition, storage, manipulation, and presentation
of data, particularly by electronic means.
information retrieval: n. The process of finding, organizing, and displaying
information, particularly by electronic means.
information science: n. The study of how information is collected, organized,
handled, and communicated. See also information theory.
Information Superhighway: n. The existing Internet and its general infrastructure,
including private networks, online services, and so on. See National Information Infrastructure.
information warehouse: n. The total of an organization's data resources on
infrared: adj. Having a frequency in the electromagnetic spectrum in the range
just below that of red light. Objects radiate infrared in proportion to their temperature. Infrared radiation is
traditionally divided into four somewhat arbitrary categories based on its wavelength. k:\compdict\database\2261.doc
Infrared Data Association: n. The industry organization of computer, component,
and telecommunications vendors who have established the standards for infrared communication between computers
and peripheral devices such as printers. Acronym: IrDA.
infrared port: n. An optical port on a computer for interfacing with an infrared-capable
device. Communication is achieved without physical connection through cables. Currently, the devices must be only
a few feet apart, and the ports aligned with one another for communication to occur. Infrared ports can be found
on some laptops, notebooks, and printers. See also cable, infrared, input/output port.
inherit: vb. To acquire the characteristics of another class, in object-oriented
programming. The inherited characteristics may be enhanced, restricted, or modified. See also class.
Initial Graphics Exchange Specification: n. A standard file format for computer
graphics, supported by the American National Standards Institute (ANSI), that is particularly suitable for describing
models created with computer-aided design (CAD) programs. It includes a wide variety of basic geometric forms (primitives)
and, in keeping with CAD objectives, offers methods for describing and annotating drawings and engineering diagrams.
See also ANSI. Acronym: IGES.
initialization: n. The process of assigning initial values to variables and
data structures in a program.
initialization string: n. A sequence of commands sent to a device, especially
a modem, to configure it and prepare it for use. In the case of a modem, the initialization string consists of
a string of characters.
initialize: vb. 1. To prepare a storage medium, such as a disk or a tape, for
use. This may involve testing the medium's surface, writing startup information, and setting up the file system's
index to storage locations. 2. To assign a beginning value to a variable. 3. To start up a computer. See also cold
ink cartridge: n. A disposable module that contains ink and is typically used
in an ink-jet printer. See also ink-jet printer.
ink-jet printer: n. A nonimpact printer in which liquid ink is vibrated or
heated into a mist and sprayed through tiny holes in the print head to form characters or graphics on the paper.
Ink-jet printers are competitive with some laser printers in price and print quality if not in speed. However,
the ink, which must be highly soluble to avoid clogging the nozzles in the print head, produces fuzzy-looking output
on some papers and smears if touched or dampened shortly after printing. See also nonimpact printer, print head.
inline image: n. An image that is embedded in a line of text rather than in
its own window.
inline style: n. A method of applying cascading style sheet properties and
values to an element on a page, such as a table, image, or ActiveX control. You can use this method even if the
page is not linked to an external style sheet or does not contain an embedded style sheet. See also cascading style
sheet, embedded style sheet, external style sheet.
inoculate: vb. To protect a program against virus infection by recording characteristic
information about it. For example, checksums on the code can be recomputed and compared with the stored original
checksums each time the program is run; if any have changed, the program file is corrupt and may be infected. See
also checksum, virus.
input1: n. Information entered into a computer or program for processing, as
from a keyboard or from a file stored on a disk drive.
input2: vb. To enter information into a computer for processing.
input device: n. A peripheral device whose purpose is to allow the user to
give input to a computer system. Examples of input devices are keyboards, mice, joysticks, and styluses. See also
input/output: n. The complementary tasks of gathering data for a computer or
a program to work with, and of making the results of the computer's activities available to the user or to other
computer processes. Gathering data is usually done with input devices such as the keyboard and the mouse, as well
as disk files, while the output is usually made available to the user via the display and the printer and via disk
files or communications ports for the computer. Acronym: I/O.
Insert key: n. A key on the keyboard, labeled "Insert" or "Ins,"
whose usual function is to toggle a program's editing setting between an insert mode and an overwrite mode, although
it may perform different functions in different applications. Also called Ins key.
install: vb. 1. To set in place and prepare for operation. Operating systems
and application programs commonly include a disk-based installation program that does most of the work of setting
up the program to work with the computer, printer, and other devices. Often such a program can check for devices
attached to the system, request the user to choose from sets of options, create a place for the program on the
hard disk, and modify system startup files as necessary. 2. To transfer one of a limited number of copies of a
program to a disk from a copy-protected program disk; a special procedure is needed because the normal method of
copying the program has been disabled.
Installable File System Manager: n. In Windows 95, the part of the file system
architecture responsible for arbitrating access to the different file system components. Acronym: IFS.
Installer: n. A program, provided with the Apple Macintosh operating system,
that allows the user to install system upgrades and make bootable (system) disks.
interactive: adj. Characterized by conversational exchange of input and output,
as when a user enters a question or command and the system immediately responds. The interactivity of microcomputers
is one of the features that makes them approachable and easy to use.
interactive session: n. A processing session in which the user can more or
less continuously intervene and control the activities of the computer. Compare batch processing (definition 2).
interactive television: n. A video technology in which a viewer interacts with
the television programming. Typical uses of interactive television include Internet access, video on demand, and
video conferencing. See also video conferencing.
interface: n. 1. The point at which a connection is made between two elements
so that they can work with each other. 2. Software that enables a program to work with the user (the user interface,
which can be a command-line interface, menu-driven, or a graphical user interface), with another program such as
the operating system, or with the computer's hardware. 3. A card, plug, or other device that connects pieces of
hardware with the computer so that information can be moved from place to place. For example, standardized interfaces
such as RS-232-C standard and SCSI enable communications between computers and printers or disks. See also RS-232-C
standard, SCSI. 4. A networking or communications standard, such as the ISO/OSI model, that defines ways for different
systems to connect and communicate.
interlaced GIF: n. A GIF (Graphics Interchange Format) image that is gradually
displayed in a Web browser, showing increasingly detailed versions of the entire image until all of the data has
finished downloading. See also GIF.
interleave: vb. To arrange the sectors on a hard disk in such a way that after
one sector is read, the next sector in numeric sequence will arrive at the head when the computer is ready to accept
it rather than before, which would make the computer wait a whole revolution of the platter for the sector to come
back. Interleaving is set by the format utility that initializes a disk for use with a given computer.
internal modem: n. A modem constructed on an expansion card to be installed
in one of the expansion slots inside a computer. Compare external modem, integral modem.
internet: n. Short for internetwork. A set of computer networks that may be
dissimilar and are joined together by means of gateways that handle data transfer and conversion of messages from
the sending networks' protocols to those of the receiving network.
Internet: n. The worldwide collection of networks and gateways that use the
TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed
data communication lines between major nodes or host computers, consisting of thousands of commercial, government,
educational, and other computer systems, that route data and messages. One or more Internet nodes can go off line
without endangering the Internet as a whole or causing communications on the Internet to stop, because no single
computer or network controls it. The genesis of the Internet was a decentralized network called ARPANET created
by the Department of Defense in 1969 to facilitate communications in the event of a nuclear attack. Eventually
other networks, including BITNET, Usenet, UUCP, and NSFnet, were connected to ARPANET. Currently, the Internet
offers a range of services to users, such as FTP, e-mail, the World Wide Web, Usenet news, Gopher, IRC, telnet,
and others. Also called Net. See also BITNET, FTP1 (definition 1), Gopher, IRC, NSFnet, telnet1, Usenet, UUCP,
World Wide Web.
Internet access: n. 1. The capability of a user to connect to the Internet.
This is generally accomplished through one of two ways. The first is through a dialing up of an Internet service
provider or an online information services provider via a modem connected to the user's computer. This method is
the one used by the majority of home computer users. The second way is through a dedicated line, such as a T1 carrier,
that is connected to a local area network, to which, in turn, the user's computer is connected. The dedicated line
solution is used by larger organizations, such as corporations, which either have their own node on the Internet
or connect to an Internet service provider that is a node. A third way that is emerging is for users to use set-top
boxes with their TVs. Generally, however, this will give a user access only to documents on the World-Wide Web.
See also dedicated line (definition 1), ISP, LAN, modem, node (definition 2), set-top box. 2. The capability of
an online information service to exchange data with the Internet, such as e-mail, or to offer Internet services
to users, such as newsgroups, FTP, and/or the World Wide Web. Most online information services offer Internet access
to their users. See also FTP1 (definition 1), online information service.
Internet access device: n. A communications and signal-routing mechanism, possibly
incorporating usage tracking and billing features, for use in connecting multiple remote users to the Internet.
Internet account: n. A generic term for a registered username at an Internet
Service Provider (ISP). An Internet account is accessed via username and password. Services such as dial-in PPP
Internet access and e-mail are provided by ISPs to Internet account owners.
Internet address: n. See domain name address, e-mail address, IP address.
Internet Architecture Board: n. The body of the Internet Society (ISOC) responsible
for overall architectural considerations regarding the Internet. The IAB also serves to adjudicate disputes in
the standards process. See also Internet Society. Acronym: IAB.
Internet Assigned Numbers Authority: n. A unit of the Internet Architecture Board that registers and
controls the assignment of various Internet-related numerical designations, such as IP port, protocol, and enterprise
numbers. Acronym: IANA.
Internet backbone: n. One of several high-speed networks connecting many local
and regional networks, with at least one connection point where it exchanges packets with other Internet backbones.
Historically, the NSFnet (predecessor to the modern Internet) was the backbone to the entire Internet in the United
States. This backbone linked the supercomputing centers that the National Science Foundation (NSF) runs. Today,
different providers have their own backbones so that the backbone for the supercomputing centers is independent
of backbones for commercial Internet providers such as MCI and Sprint. See also backbone.
Internet broadcasting: n. Broadcasting of audio, or audio plus video, signals
across the Internet. Internet broadcasting includes conventional over-the-air broadcast stations that transmit
their signals into the Internet as well as Internet-only stations. Listeners use audio Internet software, such
as RealAudio. One method of Internet broadcasting is MBONE. See also MBONE, RealAudio.
Internet Draft: n. A document produced by the IETF (Internet Engineering Task
Force) for purposes of discussing a possible change in standards that govern the Internet. An Internet Draft is
subject to revision or replacement at any time; if not replaced or revised, the Internet Draft is valid for no
more than six months. An Internet Draft, if accepted, may be developed into an RFC. See also IETF, RFC.
Internet Engineering Steering Group: n. The group within the Internet Society
(ISOC) that, along with the Internet Architecture Board (IAB), reviews the standards proposed by the Internet Engineering
Task Force (IETF). Acronym: IESG.
Internet Explorer: n. Microsoft's Web browser, introduced in October 1995.
Internet Explorer is now available in Windows and Macintosh versions. Later versions provide the ability to incorporate
advanced design and animation features into Web pages and recognize ActiveX controls and Java applets. See also
ActiveX controls, Java applet, Web browser.
Internet gateway: n. A device that provides the connection between the Internet
backbone and another network, such as a LAN (local area network). Usually the device is a computer dedicated to
the task or a router. The gateway generally performs protocol conversion between the Internet backbone and the
network, data translation or conversion, and message handling. A gateway is considered a node on the Internet.
See also gateway, Internet backbone, node (definition 2), router.
Internet Group Membership Protocol: n. A protocol used by IP hosts to report
their host group memberships to any immediately neighboring multicast routers. Acronym: IGMP.
Internet Information Server: n. Microsoft's brand of Web server software, utilizing
Hypertext Transfer Protocol to deliver World Wide Web documents. It incorporates various functions for security,
allows for CGI programs, and also provides for Gopher and FTP servers.
Internet Research Steering Group: n. The governing body of the Internet Research
Task Force (IRTF). Acronym: IRSG.
Internet Research Task Force: n. A volunteer organization that makes long-term
recommendations concerning the Internet to the Internet Architecture Board. See also Internet Society. Acronym:
Internet security: n. A broad topic dealing with all aspects of data authentication,
privacy, integrity, and verification for transactions over the Internet. For example,
credit card purchases made via a World Wide Web browser require attention to Internet security issues to help ensure
that the credit card number is not intercepted by an intruder or copied from the server where the number is stored,
and to verify that the credit card number is actually sent by the person who claims to be sending it.
Internet Society: n. An international organization, comprising individuals,
companies, foundations, and government agencies, that promotes the use, maintenance, and development of the Internet.
The Internet Architecture Board (IAB) is a body within the Internet Society. In addition, the Internet Society
publishes the Internet Society News and produces the annual INET conference. See also INET (definition 2), Internet
Architecture Board. Acronym: ISOC.
Internet Software Consortium: n. A nonprofit organization that develops software
that is available for free, via the World Wide Web or FTP, as well as development of Internet standards such as
the Dynamic Host Configuration Protocol (DHCP). See also DHCP.
internetwork: adj. Of or pertaining to communications between connected networks.
Often used to refer to communication between one local area network and another over the Internet or another wide-area
network. See also LAN, wide area network.
InterNIC: n. Short for NSFnet (Internet) Network Information Center. The organization
that is charged with registering domain names and IP addresses as well as distributing information about the Internet.
InterNIC was formed in 1993 as a consortium involving the U.S. National Science Foundation, AT&T, General Atomics,
and Network Solutions Inc. (Herndon, Va.). The latter partner administers InterNIC Registration Services, which
assigns Internet names and addresses. InterNIC can be reached by e-mail at firstname.lastname@example.org or on the Web at http://www.internic.net/.
interoperability: n. Referring to components of computer systems that are able
to function in different environments. For example, Microsoft's NT operating system is interoperable on Intel,
DEC Alpha, and other CPUs. Another example is the SCSI standard for disk drives and other peripheral devices that
allows them to interoperate with different operating systems. With software, interoperability occurs when programs
are able to share data and resources. Microsoft Word, for example, is able to read files created by Microsoft Excel.
interpreter: n. A program that translates and then executes each statement in a program written in an
interpreted language. See also compiler, interpreted language, language processor.
interrupt: n. A request for attention from the processor. When the processor
receives an interrupt, it suspends its current operations, saves the status of its work, and transfers control
to a special routine known as an interrupt handler, which contains the instructions for dealing with the particular
situation that caused the interrupt. Interrupts can be generated by various hardware devices to request service
or report problems, or by the processor itself in response to program errors or requests for operating-system services.
Interrupts are the processor's way of communicating with the other elements that make up a computer system. A hierarchy
of interrupt priorities determines which interrupt request will be handled first if more than one request is made.
A program can temporarily disable some interrupts if it needs the full attention of the processor to complete a
particular task. See also exception, external interrupt, hardware interrupt, internal interrupt, software interrupt.
interrupt handler: n. A special routine that is executed when a specific interrupt
occurs. Interrupts from different causes have different handlers to carry out the corresponding tasks, such as
updating the system clock or reading the keyboard. A table stored in low memory contains pointers, sometimes called
vectors, that direct the processor to the various interrupt handlers. Programmers can create new interrupt handlers
to replace or supplement existing handlers, such as by making a clicking sound each time the keyboard is pressed.
intranet: n. A network designed for information processing within a company
or organization. Its uses include such services as document distribution, software distribution, access to databases,
and training. An intranet is so called because it usually employs applications associated with the Internet, such
as Web pages, Web browsers, FTP sites, e-mail, newsgroups, and mailing lists, accessible only to those within the
intraware: n. Groupware or middleware for use on a company's private intranet.
Intraware packages typically contain e-mail, database, workflow, and browser applications. See also groupware,
intruder: n. An unauthorized user or unauthorized program, generally considered
to have malicious intent, on a computer or computer network. See also bacterium, cracker, Trojan horse, virus.
Invalid Page Fault: n. See page fault.
I/O: n. See input/output.
I/O controller: n. See input/output controller.
I/O device: n. See input/output device.
I/O port: n. See input/output port.
I/O processor: n. See input/output processor.
IO.SYS: n. One of two hidden system files installed on an MS-DOS startup disk.
IO.SYS in IBM releases of MS-DOS (called IBMBIO.COM) contains device drivers for peripherals such as the display,
keyboard, floppy disk drive, hard disk drive, serial port, and real-time clock. See also MSDOS.SYS.
IP: n. Acronym for Internet Protocol. The protocol within TCP/IP that governs
the breakup of data messages into packets, the routing of the packets from sender to destination network and station,
and the reassembly of the packets into the original data messages at the destination. IP corresponds to the network
layer in the ISO/OSI model. See also ISO/OSI model, TCP/IP. Compare TCP.
IP address: n. Short for Internet Protocol address. A 32-bit (4-byte) binary
number that uniquely identifies a host (computer) connected to the Internet to other Internet hosts, for the purposes
of communication through the transfer of packets. An IP address is expressed in "dotted quad" format,
consisting of the decimal values of its four bytes, separated with periods; for example, 127.0.0.1. The first one,
two, or three bytes of the IP address, assigned by InterNIC Registration Services, identify the network the host
is connected to; the remaining bits identify the host itself. The 32 bits of all 4 bytes together can signify almost
232, or roughly 4 billion, hosts. (A few small ranges within that set of numbers are not used.) See also host,
InterNIC, IP, packet (definition 2). Compare domain name.
IP address mask: n. A range of IP addresses defined so only computers with
IP addresses within the range are allowed access to an Internet service. To mask a portion of the IP address, replace
it with the asterisk wild card character (*). For example, 192.44.*.* represents every computer on the internet
with an IP address beginning with 192.44.
IPC: n. See interprocess communication.
IP multicasting: n. Short for Internet Protocol multicasting. The extension
of local area network multicasting technology to a TCP/IP network. Hosts send and receive multicast datagrams,
the destination fields of which specify IP host group addresses rather than individual IP addresses. A host indicates
that it is a member of a group by means of the Internet Group Management Protocol. See also datagram, Internet
Group Membership Protocol, IP, MBONE, multicasting.
IPng: Acronym for Internet Protocol next generation. A version of Internet
Protocol (IP) developed by the Internet Engineering Task Force (IETF). Improvements over the original Internet
Protocol include improved security features and an increased IP address size of 16 bytes. See also IETF,
IP, IP address.
IP spoofing: n. The act of inserting a false sender IP address into an Internet
transmission in order to gain unauthorized access to a computer system. See also IP address, spoofing.
IP switching: n. A technology developed by Ipsilon Networks (Sunnyvale, CA)
that enables a sequence of IP packets with a common destination to be transmitted over a high-speed, high-bandwidth
Asynchronous Transfer Mode (ATM) connection.
IPv6: n. Short for Internet Protocol version 6. A proposed next generation
for the Internet Protocol, currently version 4, which was introduced in September 1995 by the Internet Engineering
Task Force and formerly known as IPng. See also IP, IPng.
IPX: n. Acronym for Internetwork Packet Exchange. The protocol in Novell NetWare
that governs addressing and routing of packets within and between LANs. IPX packets can be encapsulated in Ethernet
packets or Token Ring frames. IPX operates at ISO/OSI levels 3 and 4 but does not perform all the functions at
those levels. In particular, IPX does not guarantee that a message will be complete (no lost packets); SPX has
that job. See also Ethernet, packet, Token Ring network. Compare SPX (definition 1).
IPX/SPX: n. The network and transport level protocols used by Novell NetWare,
which together correspond to the combination of TCP and IP in the TCP/IP protocol suite. See also IPX, SPX (definition
IRC: n. Acronym for Internet Relay Chat. A service that enables an Internet
user to participate in a conversation on line in real time with other users. An IRC channel, maintained by an IRC
server, transmits the text typed by each user who has joined the channel to all other users who have joined the
channel. Generally, a channel is dedicated to a particular topic, which may be reflected in the channel's name.
An IRC client shows the names of currently active channels, enables the user to join a channel, and then displays
the other participants' words on individual lines so that the user can respond. IRC was invented in 1988 by Jarkko
Oikarinen of Finland. See also channel (definition 2), server (definition 2).
IRQ: n. Acronym for interrupt request. One of a set of possible hardware interrupts,
identified by a number, on a Wintel computer. The number of the IRQ determines which interrupt handler will be
used. In the AT bus, ISA, and EISA, 15 IRQs are available; in Micro Channel Architecture, 255 IRQs are available;
each device's IRQ is hardwired or set by a jumper or DIP switch. The VL bus and the PCI local bus have their own
interrupt systems, which they translate to IRQ numbers. See also AT bus, DIP switch, EISA, interrupt, IRQ conflict,
ISA, jumper, Micro Channel Architecture, PCI local bus, VL bus.
IRQ conflict: n. The condition on a Wintel computer in which two different
peripheral devices use the same IRQ to request service from the central processing unit (CPU). An IRQ conflict
will prevent the system from working correctly; for example, the CPU may respond to an interrupt from a serial
mouse by executing an interrupt handler for interrupts generated by a modem. IRQ conflicts can be prevented by
the use of Plug and Play hardware and software. See also interrupt handler, IRQ, Plug and Play.
ISAPI: n. Acronym for Internet Server Application Programming Interface. An
easy-to-use, high-performance interface for back-end applications for Microsoft's Internet Information Server (IIS).
ISAPI has its own dynamic-link library, which offers significant performance advantages over the CGI (Common Gateway
Interface) specification. See also API, dynamic-link library, Internet Information Server. Compare CGI.
ISA slot: n. A connection socket for a peripheral designed according to the
ISA (Industry Standard Architecture) standard, which applies to the bus developed for use in the 80286 (IBM PC/AT)
motherboard. See also ISA.
ISDN: n. Acronym for Integrated Services Digital Network. A worldwide digital
communications network evolving from existing telephone services. The goal of ISDN is to replace the current telephone
network, which requires digital-to-analog conversions, with facilities totally devoted to digital switching and
transmission, yet advanced enough to replace traditionally analog forms of data, ranging from voice to computer
transmissions, music, and video. ISDN is built on two main types of communications channels: a B channel, which
carries data at a rate of 64 Kbps (kilobits per second), and a D channel, which carries control information at
either 16 or 64 Kbps. Computers and other devices connect to ISDN lines through simple, standardized interfaces.
When fully implemented (possibly around the turn of the century), ISDN is expected to provide users with faster,
more extensive communications services. See also channel (definition 2).
ISDN terminal adapter: n. The hardware interface between a computer and an ISDN line. See also ISDN.
ISO: n. Short for International Organization for Standardization (often incorrectly
identified as an acronym for International Standards Organization), an international association of countries of
which each is represented by its leading standard-setting organization--for example, ANSI (American National Standards
Institute) for the United States. The ISO works to establish global standards for communications and information
exchange. Primary among its accomplishments is the widely accepted ISO/OSI model, which defines standards for the
interaction of computers connected by communications networks. ISO is not an acronym; rather, it is derived from
the Greek word isos, which means "equal" and is the root of the prefix "iso-."
ISO 9660: n. An international format standard for CD-ROM adopted by the ISO
that follows the recommendations embodied in the High Sierra specification, with some modifications. See also High
ISO/OSI model: n. Short for International Organization for Standardization
Open Systems Interconnection model. A layered architecture (plan) that standardizes levels of service and types
of interaction for computers exchanging information through a communications network. The ISO/OSI model separates
computer-to-computer communications into seven layers, or levels, each building upon the standards contained in
the levels below it. The lowest of the seven layers deals solely with hardware links; the highest deals with software
interactions at the application-program level. k:\compdict\database\3778.doc
ISP: n. Acronym for Internet service provider. A business that supplies Internet
connectivity services to individuals, businesses, and other organizations. Some ISPs are large national or multinational
corporations that offer access in many locations, while others are limited to a single city or region. Also called
access provider, service provider.
italic: n. A type style in which the characters are evenly slanted toward the
right. This sentence is in italics. Italics are commonly used for emphasis, foreign-language words and phrases,
titles of literary and other works, technical terms, and citations. See also font family. Compare roman.
IVUE: n. A proprietary image format (from Live Pictures) that allows files
to be adjusted to screen resolution at any zoom level.
Many definitions maybe similar to the Microsoft Computer Dictionary,
5th Edition. Purchase information found at Microsoft Press.
The contributors of these definitions is far too numerous to mention, however
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