All technical languages breed their share of acronyms and our industry is no exception. UniForum's Open Systems Glossary contains acronyms which we believe will be of use to all members. We don't expect we've captured them all, and new ones pop up all the time. We welcome new submissions (together with short to-the-point definitions) via e-mail to pubs@uniforum.org.
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10BaseT
IEEE 802.3 LAN specification using unshielded twisted-pair wiring and running
at 10 Mbps. 10BaseT and Ethernet are very similar.
16-Bit Character Set
Character sets that require more than 200 characters, often considerably
more: 16-bit character sets of 1,000 or more characters are common. (See
Bit.)
100Base TX
See Fast Ethernet.
100VG AnyLAN
An alternative 100 Mbps specification to Fast Ethernet. 100VG AnyLAN was
sent to the 802.12 Token-Ring working group. 100VG is an attempt to make
a faster Ethernet better suited to multimedia LAN communication. (See also
Fast Ethernet.)
3-Tier System
Comprises client-middleware-legacy system or server.
4GL (Fourth-Generation Language)
High-level programming languages generally associated with database applications.
The name is derived from a comparison with languages such as C, which are
labeled 3GLs. 4GLs are increasingly associated with graphical development
tools which automatically generate the text of the programming language.
8-Bit Character Set
Character set than can be defined within the ANSI Latin-1 definition: usually
around 200 characters total. (See Bit.)
ABI (Application Binary Interface)
Application interfaces that enable binary applications to function compatibly
on operating system environments with minor differences, such as varying
implentations of Unix System V for Intel-based computers.
ACD (Automatic Call Distribution)
Telephony facility/resource that automatically routes inbound phone calls
to specific phone desksets on an enterprise PBX.
ActiveX
Microsoft's external API link that will link Microsoft compatible objects
to other external resources.
AFS (Andrew File System)
An alternative networked file system developed at Carnegie Mellon University
as part of Mach and later incorporated into the OSF/1 operating system.
(See NFS.)
Alias
A simple name substituted for a complicated name, e-mail address or company.
Used frequently as an easily remembered name for an e-mail address or a
list of e-mail addresses.
Anonymous FTP
A process for document retrieval using the FTP. The user logs on (as "anonymous")
but does not need a password to access documents on the server. (See FTP.)
ANSI-C
Second-generation specification of the C programming language accepted by
ANSI in the late 1980s. Many of the changes between K&R C and ANSI-C
simply formalized popular extensions that had been created within the programming
community, and specified a standard library.
ANSI (American National Standards Institute)
The coordinating body for voluntary standards groups within the United States.
ANSI is a member of the International Organization for Standardization (ISO).
API (Application Programming Interface)
A specification of function-call conventions that define an interface to
a service. If two incompatible computers both support the same API, then
a single version of source code should compile on each.
Applet
A Java applet; a dependent Java program that requires a Java Virtual Machine
(the JVM can be embedded either in an operating system or built into an
Internet browser).
AppleTalk
A series of related communication protocols introduced and maintained by
Apple Computer. Two phases currently exist: Phase I and Phase II. Phase
II, the more recent version, includes support for internetworks.
Application Layer
Set of related functions that provide application services between hosts.
Archie
A search device for documents using anonymous FTP server machines. It is
a system for locating information in files and directories that are publicly
available.
ARP (Address Resolution Protocol)
A method of finding a host's Ethernet address via the broadcast mechanism.
A sender using ARP broadcasts a packet containing the Internet address of
another host and waits for it (or some other host) to send back its Ethernet
address. Each host maintains a cache of address translations to reduce delay
and loading. ARP allows the Internet address to be independent of the Ethernet
address but it only works if all hosts on the net support it.
ASCII (American Standard Code for Information Interchange)
An eight-bit code for character representation; includes seven bits plus
parity. (See EBCDIC,
UniCode.)
ASIC (Application-Specific Integrated Circuit)
A custom computer chip designed to perform a specialized function, hence
application-specific.
AT/IDE (Integrated Drive Electronics)
The IBM AT hard disk controller interface that was moved off dedicated controller
cards and onto the actual drive electronics (hence the name). The IDE interface
is inexpensive and widely used but limits the system to two devices, a master
and a slave. An updated specification, called ATA, is being discussed.
ATM (Asynchronous Transfer Mode)
A CCITT standard for cell relay. Multiple types of information, such as
voice, video and data, are conveyed in small, fixed-size cells. Also, a
BISDN transfer mode wherein an accelerated version of asynchronous time
division multiplexing (ATDM) is used to move multiple streams of information
across a communication channel. ATM is both a LAN and WAN technology.
awk/nawk
awk is a text selection and alternation tool in the same family as grep
and sed. It provides a means to search for text patterns and extends the
capabilities to selecting specific fields from lines and testing relationships
between those fields. awk can be thought of as a "programmable report
generator."
Backbone in a Box
Using a router with a high-speed backbone to function as a network backbone.
All primary LAN segments are run to the router, and communication between
those segments flows at high speed. It is easy to integrate several protocols,
and the router centralizes backbone management.
Backbone Network
The central data highway that connects other networks. A backbone can be
the network infrastructure that connects several LAN segments within a building
or campus, or a national or international infrastructure connecting network
operations in various cities.
Bandwidth
The capacity of a network, usually measured in bits per second. Network
systems need higher bandwidth for audio or video than for e-mail or other
services.
Baud
The number of times per second the signal can change on a transmission line.
Usually, the baud rate equals the number of bits per second that can be
transferred.
BBS (Bulletin Board Service)
A service that permits one person to post a message for others to read.
Each bulletin board contains the discussion of a single topic. A bulletin
board is sometimes called a computer conference.
Beta Software
Preproduction, unfinished software that has not been completely tested/verified
for final release. Typically a class of software after the initial development/implementary
phase of the product life cycle.
Binary File
A file with nontext characters. Often, a directly executable file that can
be run as a program. Binary characters use all the bits in a (8-bit) byte.
(See also ASCII.)
BISDN (Broadband ISDN)
Communication standards being developed by the CCITT to handle high-bandwidth
applications such as video. BISDN can use ATM technology over SONET-based
transmission circuits to provide data rates of 155 Mbps to 622 Mbps and
beyond. Other physical layers can be used (T-1, T-3). (See BRI, ISDN and PRI.)
Bit (Binary Digit)
A unit of information; the amount of information obtained by asking a yes-or-no
question. A computational quantity that can take on one or two values, such
as true or false or 0 or 1. The smallest unit of storage -- sufficient to
hold one bit.
Bps (Bits per Second)
A measure of the rate of data transmission. Usually, the measure refers
to the capacity of a network. (See Bandwidth.)
BRI (Basic Rate Interface)
The ISDN interface composed of two B channels and one D channel for circuit-switched
communication of voice, data and video. (See BISDN
and ISDN.)
Bridge
A hardware device used to connect multiple networks by passing packets.
A bridge works at the data link layer (i.e., Layer 2 of OSI).
Broadband
Broadband communications can carry multiple types of information by allocating
different services to different frequencies. This characteristic enables
it to more easily accommodate voice, video and data.
Browser
Another term for "viewer"; that is, a software package that permits
you to look around the World Wide Web. Examples of browsers are Netscape
Navigator and Internet Explorer.
BSD (Berkeley Software Distribution)
A Unix version released by the University of Calif. at Berkeley's Computer
Systems Research Group, sold only to AT&T Unix licensees because it
contains some AT&T source code. Earlier versions of SunOS were derived
from BSD roots. A commercial implementation of BSD, cleansed of AT&T
source code, is available from BSDI.
Byte
An amount of memory or data, usually eight bits. The smallest unit of memory
referenced by an addressable unit of storage.
Byte Code
Java interpretive execution code that makes up a Java program ready for
execution.
C
A programming language originally developed by Ken Thompson and Dennis Ritchie.
C has since been extended and standardized and is used throughout the world.
C++
An object-oriented programming (OOP) extension of the C programming language.
OOP languages offer improved ability for developers to reuse software modules
but require a fundamentally different mindset in development projects.
Cable Modem
High-speed modem.
Cache Memory
Area of memory in the computer set aside for temporary storage of the data
that has most recently been taken from main memory. The computer anticipates
what data the programs in operation will need and pulls this into the cache
memory. This results in faster access and transfer of data than would be
possible if the information had to be retrieved from main memory.
Caching
Making copies of data in local, high-speed storage.
CAD (Computer-Aided Design or Drafting)
CAD and related terms are often used with varying meanings. Generally CAD
refers to the computer-based design work for architects, civil and mechanical
engineers, etc. Some call this MCAD (Mechanical CAD).
CAE (Computer-Aided Engineering)
Generally refers to the computer-based design, simulation and testing work
of electrical engineers. Some refer to this market as ECAD (Electrical CAD).
CAM (Computer-Aided Manufacturing)
Generally refers to the use of computers in the manufacturing process. Manufacturing
equipment is increasingly fitted with computer-based monitoring components,
and some are computer-controlled. Centralized, real-time computer monitoring
of manufacturing processes is now common.
CASE (Computer-Aided Software Engineering)
Computer-based software design tools (Upper CASE) and code-generation tools
(Lower CASE). CASE generally refers to software development tools intended
for the development of large, complex projects, often by large development
staffs.
CAT (Common Abstract Tree)
A universal intermediate language, used by Norsk Data in their family of
compilers. It is a multi-language compiler system with automatically generated
code generators.
CBT (Computer-Based Training)
Software applications generally designed for self-paced, independent learning.
CBT often enables trainees to work through what-if scenarios.
CCD (Computer-Created Design)
A design created by computer.
CCITT
See ITU.
CDDI (Copper Distributed Data Interface)
Standard for FDDI implementation on top of existing twisted-pair copper
cable.
CD-ROM (Compact Disk Read-Only Memory)
Generally mass produced compact disks with computer applications and data.
Data can only be read from, not written to, these optical disks. (See WORM.)
CD-RW (CD-Rewritable)
Allows users to read, write and erase data on compact disks.
CDE (Common Desktop Environment)
A specification under review by X/Open to establish a common graphical user
interface. Part of COSE.
Cell Relay
The basis of several high-speed network protocols, including the SMDS Interface
Protocol and ATM. Small, fixed-size packets, or cells, contain identifiers
specifying the data stream to which they belong. Fixed-length cells can
be processed and switched in hardware at very high speeds.
CERN
Particle physics institute located in Geneva, Switzerland. It is the home
of the World Wide Web.
CGI (Common Gateway Interface)
A program or script, usually executed on a Web server, that carries
out actions as a user clicks on active portions of a Web screen.
CGM (Computer Graphic Metafile)
A type of file used for graphics.
Character Set
Mapping of numeric values to specific characters, as with ASCII, ISO 8859
(Latin-1) and so on.
CICS (Customer Information Control System)
A transaction monitor used for large end-to-end transaction processing in
a client/server environment. Can reset and restart a transaction if it fails.
CIM (Computer Integrated Manufacturing)
An alternative term for CAM. Manufactuing equipment is fitted with computer-based
monitoring or control components and networked so that manufacturing processes
can be monitored in real time.
CISC (Complex Instruction Set Computing)
A type of CPU. CISC processors use a more complex instruction set with multiple
operand addresses, which may be out of memory. Intel 80386 and 80486 processors
are CISC CPUs. RISC processors, in contrast, are more efficient and faster.
Class
Any uniquely identified abstration of a set of logically-related instances
that share the same or similar characteristics.
Client
The computer running client software that connects to server machines holding
information. The client makes requests to a server for documents and is
responsible for displaying the information.
Client/Server Computing
The interaction between two programs when they communicate across a network.
A program at one site sends a request to a program at another site and awaits
a response. The requesting program is called a client; the program satisfying
the request is called the server.
CLI (Command-Line Interface)
A simple computer interface for commands whereby all the characters
make up a command, including additional command arguments or options.
Codeset
A particular set of characters. (See Character Set.)
Collision Detection
Process of determining when data transmission has failed because a sending
and receiving device has transmitted data simultaneously.
Compiler
A translator that produces an executable file from a collection program
source code.
Constructor
Any class or metaclass operation that constructs (i.e., instantiates) or
creates an instance (i.e., an object or class, respectively).
CORBA (Common Object Request Broker Architecture)
A specification jointly published by OMG and X/Open, to define a software
layer responsible for accepting and fulfilling requests for objects. Version
1.1 was completed in 1991. Version 2.0 is, among other things, tackling
interoperability issues.
COSE (Common Open Software Environment)
A process undertaken initially by Sun Microsystems, IBM, Hewlett-Packard,
USL (Novell) and SCO to develop com- mon sets of specifications and interfaces
to promote greater interoperability. COSE has generally deferred to X/Open's
formal standardization process where X/Open is actively addressing issues.
CPU (Central Processing Unit)
The microprocessor responsible for the core processing of computers. The
"brain" that coordinates all the computer's functions.
csh (C shell)
This script writing tool was developed at the University of California,
Berkeley, during 1979 through 1981. The C shell includes a symbolic language
to address previous commands that are entered at the command line. It executes
Bourne and Korn shells. (See ksh,
sh.)
CSMA/CD (Carrier Sense Multiple Access with Collision
Detection)
The channel access method used in Ethernet and IEEE 802.3. If two devices
transmit simultaneously, a collision occurs, and both devices wait a random
period of time before retransmission.
CSO (Central Services Organization)
A service that facilitates user and address lookup in databases.
CTI (Computer Telephone Integration)
Connection of a computer to a telephone switch and having the computer
issue commands to move calls around. Also, more generally, any interfacing
of computer and telephone systems.
Curses
A library designed at the University of California, Berkeley to draw on
a character-mode CRT screen in a terminal-independent fashion. Curses is
included with every Unix release and is now available for many non-Unix
environments, such as DOS.
DAT (Digital Audio Tape)
Refers to a specification that enables digital data to be written to tape
in a form factor similar to audio tape. Because DAT devices are generally
less expensive and smaller, they have become popular backup devices for
stand-alone personal computers.
Datagram
Communications packet that contains both data and complete address information
for the user who is to receive the data.
DBMS (Database Management System)
A generic term referring to a variety of software applications designed
to enable users to enter, store, manipulate and retrieve data. Relational
DBMSs are most common. Some low-end DBMSs, as well as large-scale mainframe
DBMSs are flat-file databases. Object DBMSs are a relative newcomer that
is popular for some applications.
DCE (Distributed Computing Environment)
DCE is an application suite developed by OSF and focused upon communications,
distributed file services, naming services and security. Both DCE and ONC,
an alternative, are supported by COSE member companies.
DDE (Dynamic Data Exchange)
An MS Windows service enabling applications to share data. For example,
DDE could enable a spreadsheet to be shared with a word-processing application.
DDK/DDI (Device Driver Kit/Device Driver Interface)
A device driver standards specification that provides a uniform interface
for compatiblity and portabitly between a hardware device and an operating
system.
DECnet
A group of communications products (including a protocol suite) developed
by Digital Equipment Corp. The most recent iteration is DECnet Phase V,
which is largely based on the OSI protocols.
DES (Data Encryption Standard)
Standard cryptographic algorithm developed by the U.S. National Bureau of
Standards (now NIST).
Destructor
Any class or metaclass operation that destroys or removes an instance (i.e.
an object or class respectively).
DFS (Distributed File System)
An element of OSF's Distributed Computing Environment (DCE) and part
of Unix SVR4. A common set of commands for NFS and RFS, providing a set
of tools for managing distributed network environments.
Digital-to-Analog Converter
An electronic device that converts a sequence of numbers into an analog
electrical signal. As one example, a D-to-A converter is needed to change
the numbers on a compact disc into sounds.
DLL (Dynamic Link Library)
Application library layer used to store components of an application software.
DMA (Direct Memory Access)
A scheme where controllers access memory on a system without CPU intervention.
For example, many PC SCSI controllers perform their own DMA to/from memory,
thus eliminating the CPU overhead found in "programmed I/O" environments
like the PC AT/IDE interface, which requires that the CPU read or write
all data from or to the IDE device.
DME (Distributed Management Environment)
An OSF suite of services and applications for distributed system and network
management.
DNS (Domain Name System)
Distributed name system used primarily to locate host IP addresses based
on host names. It consists of a hierarchical sequence of names, from specific
to general.
DPI (Dots per Inch)
The number of dots printed or displayed in one inch. Usually used to describe
printer and scanner resolutions, but sometimes to describe computer graphics
monitors.
DQDB (Distributed Queue Dual Bus)
Communication protocol proposed by the IEEE 802.6 committee for use in MANs.
DS0
Dedicated 56 kbps digital lines. DS0 lines are the most common private lines
in use. (See T-1, T-3.)
DSP (Digital Signal Processing)
A chip dedicated to processing data such as voice and music. In much the
same way as a floating-point processor offloads math functions from the
CPU, the DSP offloads a lot of the load in multimedia applications.
DSS (Decision Support System)
Orginally from IBM, designed to provide planners and decision model developers
faster methods to analyze corporate data and to make projections.
DTMF (Dual Tone Multifrequency)
Use of two simultaneous voice-band tones for dialing (such as touch tone).
DTP (Desktop Publishing)
A computing market generally referring to graphical page design and layout
software, and related peripherals. In some quarters "DTP" is developing
a low-end, amateurish, connotation, while "electronic publishing"
is used for commercial computer-based publishing work.
Dynamically Load Drivers
The ability of an operating system to load device drivers while in runtime
operation. Device drivers are loaded and linked to the operating system.
EBCDIC (Extended Binary Coded Decimal Interchange
Code)
An eight-bit character code developed by IBM for data representation in
their large mainframe computer systems.
ed
A basic editor in the Unix system. Every Unix system has ed available. ed
is a line editor; whatever operation you want to perform, you must specify
what line or lines on which to perform that operation. Copies your original
file into a buffer and lets you explore the text in whatever order you want.
EDI (Electronic Data Interchange)
The electronic communication of operation data such as order and invoices
between organizations.
EISA (Extended Industry Standard Architecture)
An alternative to the IBM PC/XT/AT ISA architecture. EISA cards are software
configured, so jumpers are eliminated, and they can access system resources
via a 32-bit bus. It also is backward-compatible to eight- and 16-bit ISA
cards.
Electronic Mail
A service that permits one to send text to another person, a group or a
computer program. Messages automatically pass from one computer to another
through computer networks and/or via modems over telephone lines. Electronic
mail software permits, for example, one to reply to a memo, save it, and
many other features. Memos are usually stored as text files.
E-mail
An abbreviation for electronic mail.
Embedded
Low-level, realtime system computing.
Encapsulation
The packaging of operations and data together into an object type such that
the data is only accessible through its interface.
ESDI (Enhanced Small Device Interface)
ESDI is an aging hard-disk controller specification, which provided substantially
better performance than the ST-506 interface. (See SCSI.)
ESQL (Embedded SQL)
The inclusion of SQL statements within another programming language (such
as C), making it easier to integrate external application modules or procedures
with a database.
Ethernet
A baseband LAN specification invented by Xerox Corp. and developed jointly
by Xerox, Intel and Digital Equipment Corp. Ethernet networks operate at
10 Mbps using CSMA/CD to run over coaxial cable. Ethernet is similar to
a series of standards produced by IEEE and referred to as IEEE 802.3.
Ethernet Address
The physical address identifying a controller board. The Ethernet address
is hard-wired on some controllers or stored in a ROM, and others allow it
to be changed from software.
Ethernet Switching
A strategy to dedicate the full bandwidth of an Ethernet connection between
two network devices, such as a workstation and a switching hub. Full duplex
switched Ethernet offers a theoretical bandwidth of 20 Mpbs (10 in each
direction), while standard switched Ethernet provides 10 Mbps.
Extranet
An extension to an intranet that has a special secured line (e.g., ATM kiosk
to a private bank network).
FAQ (Frequently Asked Questions)
FAQ is seen quite often on World-Wide Web pages. It is a place where people
can get most of their questions answered without having to contact the Webmaster.
Fast Ethernet
A proposed specification in the 802.3 Ethernet working group to boost Ethernet
speeds to 100 Mbps, and referred to as 100BaseTX. Early implementations
promise to offer automatic sensing of LAN speeds between 10 Mbps and 100
Mbps. (See also 100VG AnyLAN.)
Fast SCSI
Fast Small Computer System Interface. Protocol within the SCSI-2 standard.
Allows data to be transmitted at 10 megabytes per second and provides an
8- or 1-bit data path. (See SCSI
and SCSI-2.)
FDDI (Fiber Distributed Data Interface)
An ANSI-defined standard specifying a 100 Mbps token-passing network using
fiberoptic cable. Uses a dual-ring architecture to provide redundancy.
FIFO (First In, First Out)
A form of queuing where the order of removal from the queue is the same
as the order of insertion into the queue. Hardware FIFOs are often used
to buffer data streams between devices that may transfer data at different
rates.
File Record Level Locking
Ability of computer system to limit access by users to a record in a file.
Allows only one user at a time to access a record and prevents others from
making modifications (although record reading may be allowed).
FIPS (Federal Information Processing Standard)
A collection of standards and specifications endorsed by the U.S. government
in its attempt to achieve greater interoperability between its hardware
and software systems.
Firewall
Web software protection. System that limits access to information in an
organization's internal network.
FOIRL (Fiber-Optic Inter-Repeater Link)
Fiberoptic signaling methodology based on the IEEE 802.3 fiberoptic specification,
which allows Ethernet and IEEE 802.3 traffic to pass over fiberoptic cabling.
Frame Relay
A WAN protocol generally considered a replacement for X.25, providing more
efficient transmission. Frame Relay is offered at speeds from 56 kbps up
to T-1 speeds.
Freeware
Free software.
FTP (File Transfer Protocol)
A high-level Internet file transfer protocol, usually implemented at the
application layer.
Full Duplex (Duplex)
The ability to send communications in both directions at the same time over
a commincations link.
GIF
A graphic image format in common use.
GIS (Geographic Information System)
A category of highly visual and graphical applications designed to present
information within its geographic context, usually as an overlay to a map
or satellite image. Often used for urban growth management, natural resource
planning or to determine the best location for a retail outlet.
GNU (Gnu's Not Unix)
Developed by Richard Stallman, then of MIT, now with the Free Software Foundation,
a Unix-look-alike operating system more similar to BSD than System V.
Gopher
A distributed document retrieval system developed by the University of Minnesota.
Gopher servers organize information in a menu hierarchy, and menu selections
may reference files on other Internet hosts.
GOSIP (Government OSI Profile)
A government procurement specification for OSI protocols. Through GOSIP,
the government has mandated that all federal agencies standardize on OSI
and implement OSI-based systems as they become commercially available.
GUI (Graphical User Interface)
A general term used to distinguish newer application presentation methods,
such as Motif, OpenLook, MS Windows and Macintosh OS, from applications
displayed on character-based terminals. GUIs are characterized by multiple
overlapping, resizable windows, buttons and the ability to use pointing
devices, such as a mouse.
Half Duplex
The method of communications that allows for information to be transmitted
back and forth between a computer and a device but only in one direction
at a time.
HIPPI (High-Performance Parallel Interface)
High-performance network interface standard defined by ANSI.
Home Page
Start-up document that serves as home base for Internet explorations.
Host
A computer connected to a network. Also called a "node."
HotJava
An Internet browser that is written in the Java language and executes Java
applets.
HotPlug Peripherals
The feature/ablitiy of hardware/operating system to accept and recognize
a peripheral device for use while the computer system is in full operation.
The reverse operation of the removal of a peripheral device is also consistent
with the feature.
HTML (Hypertext Markup Language)
HTML is the page description language used to format pages for viewing on
the World Wide Web. Formatting tags are embedded in a text file. These formatting
commands are interpreted when the document is viewed with a Web browser.
A superset of HTML, called HTML+, is being proposed to extend the language.
HTML is derived from SGML and uses hypertext.
HTTP (Hypertext Transfer Protocol)
HTTP is the client-server TCP/IP protocol used on the World Wide Web for
the exchange of documents.
Hub
A device used to connect several other devices together, e.g. in a hub/spoke
architecture, a central connection box, or hub, is used to pass messages
or data from a computer to one or more other computers connected to the
hub.
Hyperlink
Word or graphic in a file displayed on screen with some form of highlighting
(color or underlining or both). The word or graphic represents hidden text
containing the URL information of another document, which is displayed when
you click on the highlighted word or graphic.
Hypertext
A system for storing pages of textual information that each contain embedded
references to other pages of information.
I/O (Input/Output)
Input and output of text from software or hardware.
IAB (Internet Architecture Board)
The group responsible for guiding the research and development of the Internet.
They are all volunteers who attend to hear about the latest developments
and participate in efforts to refine and improve the software. It has two
task forces: the IETF and the IRTF.
IDL (Interface Definition Language)
See OMG.
IEEE (Institute of Electrical and Electronics Engineers)
A professional and trade association that also promulgates information industry
standards. IEEE LAN standards are the predominant LAN standards today, including
protocols similar or virtually equivalent to Ethernet and Token Ring. (See
Posix.)
IEEE 802.3
LAN protocol that specifies an implementation of the physical layer and
MAC sublayer of the link layer. IEEE 802.3 uses CSMA/CD access at a variety
of speeds over a variety of physical media. One physical variation of IEEE
802.3 (10Base5) is very similar to Ethernet.
IEEE 802.6
IEEE MAN specification based on DQDB technology. It supports data rates
of 1.5 Mbps to 155 Mbps, and also supports data packets and circuits.
IETF (Internet Engineering Task Force)
The primary subgroup responsible for technical matters within the IAB.
Implementation
A working version of a specification, such as a programming language or
an application.
Information Superhighway
A term used by the popular press to refer to the emerging national information
infrastructure in the United States. The Internet is the best example of
the first part of the information infrastructure.
Instantiation
The process of construction of a new instance from its definition using
a constructor.
Internet
The Internet consists of thousands of computer networks interconnected by
routers. It is an extensive computer network that is accessed through the
telephone system making it possible to reach millions of people all over
the world. The IP transforms a collection of networks and routers into a
seamless communication system by making the Internet function like a single,
large network.
InterNIC
Cooperative activity between the National Science Founcations, Network Solutions,
Inc and AT&T. InterNIC provides IP and domain name registration services
for the Internet community such as domain administrators, network coordinators
and Internet service providers.
Intranet
A company internal, enterprise or campus internet; either separate or connected
to the Internet via a protective firewall.
IP (Internet Protocol)
A Layer 3 (network layer) protocol that contains addressing information
and some control information that allows packets to be routed. (See TCP/IP.)
IPX (Internetwork Package Exchange)
Novell Layer 3 protocol similar to XNS and IP that is used in NetWare networks.
IRQ (Interrupt Request Line)
A hardware signal (bus line) that allows a peripheral device to request
processing by the CPU.
IS (Information Systems)
Information pertaining usually to computer systems.
ISA (Industry Standard Architecture)
The name given to the original PC/XT/AT bus designed by IBM in the early
1980s. The bus supports both eight- and 16-bit-wide devices as well as a
degree of board vendor independence. (See EISA, MCA.)
ISAM (Indexed Sequential Access Method)
A somewhat crude but effective database format that originated in the mainframe
world. Records in the database are logically accessed sequentially, by walking
through the database index in the desired order.
ISDN (Integrated Services Digital Network)
Communication protocols used by telephone companies to permit telephone
networks to carry text, voice and other types of data. ISDN typically operates
at 56/64 kbps. (See BRI, BISDN,
and PRI.)
ISO (International Organization for Standardization)
An international organization that is responsible for a wide range of standards,
including those relevant to networking. ISO is responsible for the well-known
OSI networking reference model. Often incorrectly referred to as the International
Standards Organization.
ISP (Internet Service Provider)
A company that provides customers with a connection to the Internet. The
connection can range from just supplying an e-mail address, to hosting a
Web site, to installing a fast connection to the Internet.
IT (Information Technology)
Information pertaining to technology.
ITU (International Telecommunications Union)
The renamed CCITT. The standards setting functions are handled by the ITU-T,
the Telecommunications Standardization Sector.
IVR (Interactive Voice Response)
A system to automate the retrieval and processing of information by
telephone, using touchtones instead of a computer keyboard. IVRs use digitized
human voices to present information to the user. (See VRU.)
Java
A computer programming language and computer software platform developed
by Sun Microsystems that is open, object-oriented in architecture, has interpretively
executed programs, and requires lightweight Java Virtual Machine to execute
Java programs on virtually any operating system or hardware platform. This
is especially well-suited for the Internet/intranet and small "intelligent"
devices (appliances) such as cellular phones or pagers.
Java Application
Independent stand-alone Java program that only requires the Java runtime
engine. This contrasts with the Java applet which requires the JVM in an
Internet browser.
Java Object Environment (JOE)
Java API for the object request broker (ORB).
Java Virtual Machine (JVM)
A Java program execution utility that is usually built into an Internet
browser.
JavaBeans
Java platform supplementary API that will link Java executables to other
external resources.
JIT Compiler
Just-In-time compiler usually in context of Java byte code compiler to native
code.
JPEG (Joint Photographic Experts Group)
The original name of the committee that designed the standard image compression
algorithm. The algorithm, JPEG, is designed for compressing either full-color
or grey-scale digital images of "natural," real-world scenes.
Jughead (Jonzy's Universal Gopher Hierarchy Excavation And Display)
A tool for gopher administrators to get menu information from various gopher
servers across the Internet.
K&R C (Kernigan & Ritchie C)
The original C programming language as specified by Brian W. Kernighan and
Dennis M. Ritchie. C is a relatively low-level, highly portable, general-purpose
programming language created by Ritchie on the Unix operating system. (See
ANSI-C.)
Kanji
Japanese character set.
Kbps (Kilobits per second)
Data transmission rate of 1,000 bits per second. (See Bit.)
Kermit
A popular, public-domain file-transfer program.
Kernel
The part of the operating system that provides memory management, I/O services
and all other low-level services. The kernel is the "core" or
"heart" of the operating system.
ksh (Korn shell)
The Korn shell is the third of the three standard shells to be incorporated
into the standard Unix environment. It used both sh and csh. It allows the
user to access vi or emacs to edit commands. (See csh, sh.)
LAN (Local-Area Network)
A network covering a relatively small geographic area (usually not larger
than a building or campus). Compared to WANs, LANs are usually characterized
by relatively high data rates and relatively low error rates. (See WAN, MAN.)
LEC (Local Exchange Carrier)
Local telephone companies, including the RBOCs and other specialty and private
companies.
Lexus/Nexus
Legacy proprietary online database resource.
LIFO (Last In, First Out)
Better known as a "stack," a LIFO queue behaves opposite of a
FIFO queue. A LIFO queue only allows access to the most recently queued
item, then the next most recently, etc. This form of queuing is most often
used to "stack" the return addresses when performing subroutine
calls.
Linux
A Unix-like operating system originally developed by Linus Torvolds for
freeware/shareware distribution.
Listserver
Software that distributes e-mail messages to registered subscribers such
as major-domo, listserv, etc. Automates almost all the processes necessary
to enable distributed discussion groups via e-mail.
LZ/LZW
Lempel-Ziv type data compression algorithm. Developed by Abraham Lempel
and Jacob Ziv in the late 1970s.
make
A utility oriented towards easy maintenance of computer programs. It helps
the process of going from the original source text of a computer program
to the final executable form of that program.
MAN (Metropolitan-Area Network)
Generally, a network that spans a larger geographic area than a LAN but
a smaller geographic area than a WAN. (See DQDB.)
Mbps (Megabits Per Second)
Data transmission rate of 1 million bits per second. (See Bit.)
MCA (Micro Channel Architecture)
An IBM proprietary bus architecture used in most of the PS/2 series of machines
and the RS/6000 line of workstations and servers. The architecture supports
multiple CPUs on the bus, like EISA and unlike ISA.
MFLOPS (Million Floating-Point Operations Per Second)
A measurement of speed in handling complex calculations, based on floating-point
arithmetic. (See MIPS.)
MHS (Message-Handling System)
A CCITT X.400 recommendation that provides message handling services for
communications between distributed applications. NetWare MHS is a different,
although similar, entity that also provides message-handling services and
is marketed by Novell.
MHz (Megahertz)
Millions of Hertz (cycles per second). MHz is an indication of frequency,
often used to refer to the clock speed at which a given processor or bus
runs. It is named to honor Heinrich Hertz.
Middleware
Set of services independent of the operating system that is used to make
development of application software easier, e.g. drivers and application
programming interfaces. Isolates the application development from the specifics
of an operating system or networking protocol, providing the communication
requirements related to distributed applications.
MIF (Maker Interchange Format)
A text format used by FrameMaker to exchange files across platforms.
MIME (Multimedia Internet Mail Extensions)
A method of processing multipart, multimedia messages on the Internet.
MIPS (Million Instructions Per Second)
The performance measure for modern CPUs. (See MFLOPS.)
MIS (Management Information Systems)
Generally refers to corporate business computing services and the department
responsible for them.
Mosaic
NCSA's browser (client) for the World Wide Web. Mosaic is a true second-generation
Internet client application for browsing HTML documents on the World Wide
Web. It supports full multimedia capabilities, and has been extended to
access gopher servers, as well as handle news and e-mail. It is now being
licensed and bundled with some operating systems.
Motherboard
CPU board.
Motif
A graphical user interface developed by OSF and now endorsed as part of
COSE.
MPEG (Moving Pictures Experts Group)
An ISO committee that generates standards for digital video compression
and audio. Also the name of their algorithm.
MRP (Manufacturing Resource Planning)
Computer systems and software used in planning and procurement of materials.
MTA (Message Transfer Agent)
An element of the X.400 standard. The part of an e-mail system that routes
messages to their destinations.
MTBF (Mean Time Between Failures)
An indication of expected duration between successive failures of a given
device. MTBF ratings are usually specified to give an indication of the
expected or predicted reliability under specific operating conditions. For
example, most disk drives today have predicted MTBF values between 100,000
and 800,000 hours.
Multitasking
Ability of an operating system to preform more than one task or run more
than one program at a time.
NAS (Network Applications Support)
A broad middleware architecture designed by Digital Equipment Corp. to enable
application interoperability over a network of heterogeneous computer systems.
NC (Network Computer)
A device designed to deliver networked information and applications
to the user. It is a low-cost, low-horsepower, processor-neutral and OS-neutral
hardware platform able to run Internet client applications.
NCSA (National Center for Supercomputing Applications)
The birthplace of the first version of the Mosaic World Wide Web browser,
at the University of Illinois at Urbana-Campaign, IL.
Net, The
A term for two particular networks: Usenet and Internet. For instance, "I
read it on the Net" or "You can get that file on the Net."
NetBios (Network Basic Input/Output System)
Software interface for a controller on personal computer local-area networks.
Accepted standard for Token Ring interface. (See LAN.)
NetWare
A network management architecture, operating system and related applications,
commercially developed and sold by Novell.
Network
Hardware and software data communications system. Networks are often also
classified according to their geographical extent: LAN, MAN and WAN, and
also according to the protocols used.
Network Link Layer or Network Layer
The network layer (e.g., Internet Protocol) is responsible for routing or
determining the links necessary to get data from the sending to the receiving
host. (See TCP/IP).
NFS (Network File System)
As commonly used, a distributed file system protocol suite developed by
Sun Microsystems that allows remote file access across a network. In actuality,
NFS is simply one protocol in the suite. RNFSS protocols include NFS, XDR
(External Data Representation), RPC (Remote Procedure Call) and others.
These protocols are part of a larger architecture that Sun refers to as
ONC (Open Networked Computing).
NIST (National Institute of Standards and Technology)
Formerly the National Bureau of Standards (NBS), this U.S. government organization
supports and catalogs a variety of standards.
NMS (Network Management System)
A system responsible for managing part of a network. An NMS is generally
a reasonably powerful and well-equipped computer such as an engineering
workstation, with a megapixel color display, large memory and disk space,
and a fast processor. NMSs communicate with agents to help keep track of
network statistics and resources. (See SNMP.)
NNTP (Network News Transfer Protocol)
A common method by which articles are transferred over Usenet.
NOS (Network Operating System)
Any operating system designed to operate and manage a computer network.
nroff
A text formatting program that is designed for use with laser printers and
professional typesetting equipment. It supports only monospaced fonts and
was developed before troff was written.
NSF (National Science Foundation)
A federally funded organization that manages the NSFnet, which connects
every major research institution and campus in the United States.
NuBus
Apple Computer's bus architecture used in its Macintosh systems.
OCR (Optical Character Recognition)
The ability to scan text and have the computer recognize letters, words
and text formats on a page. OCR enables computers to turn images of documents
into text files that can be edited in word-processing applications.
ODBMS (Object Database Management System)
Sometimes referred to as Object-Oriented DBMS. ODBMSs emphasize data classes
and methods. Proponents claim object databases excel at storing complex
groups of data as single objects. Examples might include a parts schematic
or CAD diagram.
OEM (Original Equipment Manufacturer)
Use varies, but refers to the manufacturer or designer of a technology,
which then licenses the technology to another company.
OLAP (On-Line Analytical Processing)
Database processing that supports advanced decision support, often using
a multidimensional database.
OLE (Object Link Environment)
The compound document protocol from Microsoft that allows one document to
be linked to or embedded in another.
OLTP (On-Line Transaction Processing)
Database processing that supports data entry at high speeds, such as traditional
high-volume order-entry applications.
OMG (Object Management Group)
An industry group promoting standards for exchanging objects in an interoperable
manner, perhaps best known for its work on CORBA.
OMT (Object Modeling Technique)
An object-oriented programming strategy.
ONC (Open Network Computing)
Sun Microsystems network protocols.
Open Group, The
An organization created through the combination of the Open Software Foundation
(OSF) and X/Open Co., dedicated to the furtherance of open systems.
OpenGL
Graphics platform (library and graphics standards).
OpenLook
The graphical user interface developed by AT&T and Sun Microsystems.
Until recently, a competitive peer to Motif. With COSE, Sun has acquiesced
to Motif as the standard Unix windowing environment.
ORB (Object Request Broker)
The OMG client request manager. A standard for passing objects among
heterogeneous computers on a network.
OS (Operating System)
The software on a computer that manages all the resources of the system,
including file system management, memory, reading and writing files, scheduling
processes, printing and communication.
OSF (Open Software Foundation)
An industry consortium responsible for the development of Motif, OSF/1,
DCE and DME. One of the constituent organizations of The Open Group.
OSI (Open System Interconnection)
An international standardization program created by ISO and CCITT to develop
standards for data networking that facilitates multivendor equipment interoperability.
The OSI seven-layer model is frequently used to describe the various levels
of network technology.
Overloading
Any polymorphism whereby the same name or operation is overloaded for different
but analogous abstractions or uses. Also operator overloading.
PA-RISC (Precision Architecture-RISC)
Hewlett-Packard's microprocessor architecture.
Packet
A unit of data sent across a network.
PBX (Private Branch Exchange)
A telephone switch on the user's premises.
PC (Personal Computer)
A general-purpose single-user microcomputer designed to be operated by one
person at a time.
PCI (Peripheral Component Interconnect)
A self-configuring personal computer local bus designed by Intel. It runs
at 33 MHz. It is currently used mostly on Pentium-based computers, but is
processor independent and so can work with other processor architectures
such as PowerPC and Motorola 680X0 series.
PCL (Printer Control Language)
A proprietary vendor- and device-specific control language used for laser
printer control defined by Hewlett-Packard in the 1980s.
PCMCIA (PC Memory Card International Association)
An industry standard covering the mechanical and electrical specifications
needed to interface to these credit card-size hard disks, modems, network
adapters and memory cards with computer systems.
PDF (Portable Document Format)
Designed by Adobe Systems specifically to aid in the transfer of documents
across platforms. PDF is a file format used to represent a document in a
manner independent of the application software, hardware and operating system
used to create it.
Perform
Based on Tcl/Tk, a higher level of language integration.
Perl (Practical Extraction and Report Language)
A freeware interpretive scripting language that is ideally suited for data
manipulation. Originally developed by Larry Wall.
PEX (PHIGS Extensions to X)
A combination of the X Window system and PHIGS designed to create a networked,
interoperable 3-D graphics environment.
PGP
Pretty Good Privacy encryption software (freeware).
PHIGS (Programmer Hierarchical Interactive Graphics
System)
An ANSI/ISO standard 3-D graphics programming library that runs on almost
all graphics computers, from laptops to supercomputers.
Plan 9
A distributed operating system designed by Lucent (AT&T-Bell Labs) and
the Richie, Thompson, Kernighan, Pike Bell Labs group.
POS (Point of Sale)
Essentially a computer-based cash register. As the retail industry is increasingly
computerized, most POS systems are computers with specialized peripherals,
networked to an in-store server.
Posix (Portable Operating System Interface)
IEEE's standardization effort to promote interoperable computing interfaces
and specifications.
PostScript
A device- and resolution-independent page definition language developed
by Adobe Systems, popularized with laser printers, and used to compose documents
one page at a time before printing.
PPP (Point-to-Point Protocol)
A successor to SLIP, this protocol provides router-to-router and host-to-network
connections over synchronous and asynchronous circuits. (See SLIP.)
PRI (Primary Rate Interface)
ISDN interface to primary rate access. Primary rate access consists of a
single 64 kbps D channel plus 23 (in the case of the 1.544 Mbps) or 30 (in
the case of 2.048 Mbps) B channels for voice and/or data. (See BISDN, ISDN.)
Protocol
The rules two or more computers must follow to exchange messages. A protocol
describes both the format of data that can be sent, as well as the way a
computer should respond.
Proxy ARP (Address Resolution Protocol)
The technique in which one host, usually a router, answers ARP requests
intended for another machine. By "faking" its identity, the router
accepts responsibility for routing packets to the "real" destination.
Proxy ARP allows a site to use a single IP address with two physical networks.
Public Key Encryption
An encryption scheme using two keys, one public and the other private. The
message is encrypted using the intended recipient's public key. The message
can only be decrypted by the recipient using the recipient's private key.
(See also RSA.)
QBE (Query By Example)
A form of database query where the user enters a form of the database query
rather than having to enter actual SQL commands.
QIC (Quarter-Inch Cartridge)
An industry standard form factor that covers tape capacities from 20 megabytes
to several gigabytes. The QIC committee provides media specifications, the
actual format of the data tracks on the tape and interoperability specifications.
QuickTime
A digital video format developed by Apple Computer that integrates synchronized
video and audio with compression techniques.
RAID (Redundant Array of Independent Disks)
A product niche where multiple hard-disk drives in a single enclosure operate
in unison to increase read/write throughput, and/or increase data integrity
and high availability, by continuing to function even if a single drive
fails. The RAID Advisory Board has designated RAID levels 0-5 as a standard
way for vendors to specify how their products read and write data.
RBOC (Regional Bell Operating Company)
The "Baby Bell" phone companies created in the divestiture of
AT&T, such as NYNEX, Pacific Bell, Bell South and Ameritech.
RCS (Revision Control System)
A publicly available source code control system developed at Purdue University.
Most Berkeley-style Unix vendors ship RCS but not as part of their official
OS distribution. The System V counterpart to RCS is SCCS.
RDBMS (Relational Database Management System)
The de facto database paradigm that is the core for the new generation of
client/server application infrastructures being developed. Relational databases
supply tables of rows and columns, making it possible to access data in
a more flexible manner than in heirarchial databases.
Reusability
The ease with which software may be used for purposes other than those originially
intended.
RF (Radio Frequency)
Generic term referring to frequencies that correspond to radio transmissions.
Cable TV and broadband networks use RF technology. RF is also being used
to communicate between handheld client computers and database servers.
RFC (Request for Comments)
Documents used as the primary means for communicating information about
the Internet. Some RFCs are designated by the IAB as Internet standards.
Most RFCs document protocol specifications such as Telnet and FTP, but some
are humorous and/or historical. RFCs are available from the Internet Network
Information Center.
RFP (Request for Proposal)
A document generally issued by a prospective purchaser of technology systems,
describing their requirements so that prospective sellers can respond with
detailed proposals.
RFS (Remote File System)
An alternative networked file system to NFS and AFS.
RISC (Reduced Instruction Set Computing)
RISC processors employ a more simple instruction set that generally executes
within a single clock cycle and makes better use of the chip's registers.
This combines to provide far faster processing than chips with a CISC architecture.
RMON-MIB (Remote Monitoring - Management Information
Base)
A standard developed by the Internet Engineering Task Force (IETF) recently
finalized for Ethernet, but still in transition for Token Ring networks.
A key benefit of the RMON-MIB is that it requires less network traffic and
overhead than proxy agents.
Robust or Robustness
Ability of a system to continue to operate while handling internal or hardware
errors.
ROM (Read-Only Memory)
See CD-ROM.
Router
A router can interconnect two networks that use different technologies.
Therefore a router can connect a LAN to another LAN, to a WAN, or a WAN
to another WAN.
RPC (Remote Procedure Call)
NFS interface for interhost connectivity over a network.
RS-232
Asynchronous, bidirectional bit-wide data standard typically used to connect
peripherals (modems, printers, terminals) to computers.
RSA
The initials of the authors of a study on encryption and decryption regarding
computer security. RSA Data Security Company markets public-key or dual-key
encryption technology, widely used in security products.
RTF (Rich Text Format)
A file interchange format from Microsoft to facilitate document exchange.
RTOS (Real-Time Operating System)
A mode of action and reaction by an operating system and application software.
It allows priorities to be changed instantly and data to be processed rapidly
enough that the results may be used in response to another process taking
place at the same time, as in transaction processing. It has the ability
to immediately respond, in a predetermined and predictable way, to external
events.
SAA (System Application Architecture)
A broad architecture defined by IBM to integrate applications across its
proprietary systems that uses SNA as its communications layer.
SBus
The bus architecture used on most Sparc workstations. Sparc multiprocessing
systems generally use an additional CPU/Memory architecture (MBus).
Scalability
Ability of a computer system to be optimized to perform a specific function
by adjusting the size of the central processing unit and the throughput
to the needs of the application software being run.
SCCS (Source Code Control System)
A version-control utility incorporated in Unix System V implementations.
RCS is an alternative publicly available versioning system.
SCSI (Small Computer Systems Interface)
Widely used byte-wide controller interface specification standard on workstations
and Macintoshes which is capable of transfering 5 Mbps. Peripherals of different
types (hard disks, scanners) can be combined on one SCSI bus.
SCSI-2
Newer SCSI specification that supports a 10 Mbps data transfer rate and
a broader range of devices. SCSI-2 is becoming more common on high-performance
systems.
SDL (Specification and Description Language)
CCITT specification language with both graphical and character-based syntaxes
for defining interacting extended finite state machines. Used to specify
discrete interactive systems such as industrial process control, traffic
control and telecommunication systems.
SDLC (Synchronous Data Link Control)
Synchronous communications protocol that allows data to be transferred bit
by bit.
sed (stream editor)
The stream editor is a non-interactive text editor. sed works on your file
from the beginning to the end and allows you no choice of edit commands
once you have invoked it. It is a text editor that is used to make modifications
to the content of a file. It is designed to deal with files containing strings
of characters in a particular character set. sed is ideal for changes of
a transient nature, rather than permanent modifications to a file.
Semaphore
Software locking device.
Server
The computer that provides services (documents, software) to other machines
that run specific software (clients) and request those services. (See Client/Server Computing.)
SGID
Group id. (See SUID.)
SGML (Standard Generalized Markup Language)
An ISO standard designed to ensure that electronic documentation is interoperable
between dissimilar hardware and software systems. SGML is increasingly being
adopted as a requirement by commercial and governmental organizations.
sh (Bourne shell)
The Bourne shell in Unix that is used for script writing. It is the most
common shell for software testing purposes. (See csh, ksh.)
Shareware
A class of software that is made available at low or no initial cost but
requests some cost later for full support or useage.
SIMM (Single In-line Memory Module)
A small circuit board populated with memory chips. SIMMs are considered
more convenient to work with than placing or exchanging individual memory
chips on a board.
SLIP (Serial Line Internet Protocol)
A protocol used to run IP over serial lines such as telephone circuits via
a modem or leased lines.
SlurP
A popular shareware program that emulates a PPP link within a standard Unix
shell account environment link.
SMDS (Switched Multimegabit Data Service)
A high-speed, packet-switched WAN technology offered by some RBOCs and Interexchange
carriers. SMDS is generally run at speeds between DS-1 and DS-3.
SMP (Symmetrical Multiprocessing)
A multiprocessor design where all the processors have equal status versus
the master and slave relationship of asymmetric multiprocessing. The processors
are identical and share common memory; each runs its own copy of the operating
system kernel. With SMP, processes are not tied to a specific processor
and can be run by any available processor.
SMTP (Simple Mail Transfer Protocol)
A protocol for electronic mail services popular in Internet environments.
SNA (Systems Network Architecture)
Developed by IBM, it defines the rules for transmitting and receiving data
between mainframe computers and dumb terminals over a network.
Sniffer
A device that can "sniff" or detect LAN packets for analysis.
SNMP (Simple Network Management Protocol)
An Internet network management protocol that provides a means to monitor
and set network configuration and run-time parameters.
SNMP-2 (Simple Network Management Protocol - Version
2)
An update of the SNMP standard by the Internet Engineering Task Force (IETF).
One enhancement addresses the security of network management packets.
Sockets
A combination of the port address and the network address used to uniquely
identify processes operating a specific node of a network.
SONET (Synchronous Optical Network)
High-speed synchronous network standard. Used by RBOCs as a transmission
system for voice and data. (See ATM.)
Spamming
Indiscriminate and unwelcome Internet advertising. Viewed as abuse of NES
groups and listserver-based discussion groups.
Sparc (Scalable Processor Architecture)
The microprocessor architecture popularized by Sun Microsystems.
SPECfp
A floating-point performance measure developed by the Systems Performance
Evaluation Cooperative, an industry consortium. SPECfp is the geometric
mean of six floating-point performance benchmarks.
SPECInt
An integer performance measure developed by the Systems Performance Evaluation
Cooperative, an industry consortium. SPECInt is the geometric mean of four
integer performance benchmarks.
SQL (Structured Query Language)
A higher-level language used for database applications. ANSI has certified
both a 1989 and a 1992 SQL standard.
SS7
System Signaling 7, a packet switching standard established by ANSI and
ITUTSS (CCITT).
ST-506
(1) An early 1980 hard disk-drive interface specification named after the
industry standard 5 MB (yes, five megabytes) formatted capacity. (2) A 5.25-inch
disk drive using MFM encoding. (See ESDI, SCSI.)
SUID
User id. (See SGID.)
SVR4 (System V Release 4)
The latest major release of the Unix operating system from Novell's Unix
Systems Group, and the release on which most Unix implementations are based.
System V
The current generation of the Unix operating system produced by AT&T.
The two most significant previous generations were System III and Version
7.
T-1
Digital leased-line supporting 1.54 Mbps (DS-1).
T-3
Digital leased-line supporting 44.7 Mbps (DS-3).
TAPI
Microsoft's Telephony Application Programming Interface that provides a
computer telephony interface (CTI) platform.
Tcl/Tk
A scripting language (pronounced Tickle).
TCP/IP (Transmission Control Protocol/Internet Protocol)
The two best-known Internet protocols, often erroneously thought of as one
protocol. TCP corresponds to Layer 4 (the transport layer) of the OSI reference
model, and provides reliable data transmission. IP corresponds to Layer
3 (the network layer) of the OSI reference model and provides connectionless
datagram service. TCP/IP was developed by the U.S. Department of Defense
in the 1970s to support the construction of worldwide internetworks.
Telnet
This utility allows the user to log into a remote computer over a network
(such as the Internet) using TCP/IP. The user can work on a remote computer
as if it were their local computer. The telnet program is available on many
operating systems.
Template
A class template specifies how a family of individual classes can be constructed.
Terminal Emulator
A program that makes a computer display act like a terminal. For example,
many terminal emulator programs emulate the Digital Equipment Corp. VT100
terminal.
TeX
Page formatting language with capabilities similar to troff, written by
Donald Knuth of Stanford.
Thick Client
Clients are devices and software that require information. A client
is a name fo a PC on a local area network. It used to be called a workstation.
Now it is the "client" of the server. Clients come in two varieties,
Thick and Thin. Thick clients are generally the full PC platform, which
is fully functional offline, but can still exploit a network connection.
Thin Client
The Thin client stores and processes more data on the server, but keeps
the user interface and application functions on the client device. Thin
clients can access a broad range of applications, but depend primarily on
remote resources on a network. The Thin client will be used as a potential
way to reduce the capital and support costs of end-user computing. It will
be most useful in enterprises where network dependency is increasing.
Thread
A term in multiprocessing or parallel processing for independent basic units
of computation or action.
Throughput
A measurement of a computer's productivity in the amount of data that is
usefully processed in a set period of time.
TIFF
A common graphic image file format.
Token Ring
Local area data communications network that uses a ring topology and was
developed by IBM Corp. It is the process of passing a short electronic message,
called a token, in sequential order. A host on the network cannot access
the network until it receives the token. Once the host has completed the
transmission, it releases the token. A Token Ring network transfers data
at 4 megabits per second or 16 megabits per second. Depending on the type
of wiring used, up to 270 devices, including mainframe, mini- and microcomputers,
can be connected to this kind of network.
TPM (Transaction Processing Monitor or Manager)
Provides the ability to optimize response time and throughput, realtime
database access and manage multiple concurrent updates of data. It is the
element of an online transaction processing system which manages the sequence
of multiple transactions, routing, load balancing, scalability, fault resistance
and recovery from failures.
troff
A text formatting program designed for use with laser printers and professional
typesetting equipment. troff can support proportionally spaced fonts. (See
nroff.)
Try-n-Buy
A class of software that is available for limited use with "locks"
that when "unlocked" make it for unlimited use.
TSAPI
Novell and AT&T's Telephony System Application Programming Interface
that provides a CTI platform.
TSR (Terminate and Stay Ready or Resident)
A program strategy used to work around the inherently single-user, single-tasking
nature of MS DOS. Examples of common TSRs include print spoolers, keyboard
enhancers and memory managers.
Two-Phase Commit
Distributed process protocol under which transactions must be accepted or
rejected by all the hosts on a network. A resource manager for load balancing,
in which the system's work load is spread out equally among its resources.
In the first phase, the protocol checks the network to determine if the
message may be sent. In the second phase, the receiving system indicates
if it can receive the message. Used to ensure an all-or-nothing guarantee
of the completion of a database transaction.
UltraNet
High-speed network developed by Ultra Network Technologies. Supports up
to 125 Mbps.
UltraSparc
64-bit Version 9 Sparc microprocessor architecture used by Sun Microsystems,
HaL Computers and licensees.
UniCode
A two-byte character set developed by the UniCode Consortium, which was
incorporated in 1991. UniCode integrates ASCII, Latin character sets and
Far Eastern languages into a single character set.
Unified Messaging System
The unification of various communication messaging types into one concise
(i.e., E-mail, Fax and voice mail) user management system.
Unshielded Twisted Pair
Standard telephone cable, rated at Category 3 or above. (See 10BaseT.)
UPS (Uninterruptable Power Supply)
A family of battery devices from multiple vendors that take over when normal
electrical power fails. Their size, sophistication and cost vary widely.
URL (Universal Resource Locator)
An addressing syntax used on the Internet and used extensively on the World
Wide Web. URLs generally have the form service://address, such as "http://www.uniforum.org."
URLs can also specify ftp, news, mail and other internet host servers.
Usenet
Usenet is a collection of thousands of computers worldwide that exchange
files called news articles. This "net news" system has
hundreds of discussion groups, from technical topics to art.
UUCP (Unix-to-Unix Copy Program)
A Unix file transfer application that is the basis for some E-mail systems.
v.22
An international standard for 1200 bps data transmission.
v.22 bis
An international standard for 2400 bps data transmission.
v.32
An international standard for 9600 bps data transmission.
v.32 bis
An international standard for 14.4 kbps data transmission.
v.34
A new modem serial line protocol that covers 19.2 kbps, 24.4 kbps and 28.8
kbps. With v.42 bis data compression, effective throughput can top 200 kbps.
(See also v.Fast.)
v.42
An international standard error-correction protocol.
v.42 bis
An international standard error-correction protocol that added data compression
to the V.42 standard, allowing for speeds up to 57.6 kbps.
v.Fast
The working name for the new v.34 standard that covers 19.2 kbps, 24.4 kbps
and 28.8 kbps.
VAR (Value-Added Reseller)
A term whose meaning varies widely. Often a company that sells its own software
together with another firm's software or hardware.
Veronica (Very Fast Rodent Oriented Net-wide Index to Computer Archives)
A service that maintains an index of titles of gopher items and provides
keyword searches of those items. Veronica does for gopher servers what archie
does for FTP servers.
VGA (Video Graphics Array)
IBM Corp. color video monitor with 640 x 480 pixel resolution and capable
of displaying 256 colors. Also can provide black-on-white grayscale. Provides
excellent resolution for use with graphics packages.
vi/emacs
Names of two text editors found on almost every Unix operating system.
Visual Basic
Basic programming language package by Microsoft.
Visual C++
Microsoft product of C++.
VRML (Virtual Reality Markup Language)
Language based on the Inventor file format from Silicon Graphics. Inventor
is a mature file format used for 3D graphics.
VRU (Voice Response Unit)
A system to automate the retrieval and processing of information by
telephone, using touchtones instead of a computer keyboard. VRUs use digitized
human voices to present information to the user. (See IVR.)
VT100/VT200
DEC terminal types.
WAIS (Wide-Area Information Servers)
WAIS is an index and retrieval system. When a keyword is entered, a search
is performed on indexed documents, which then can be retrieved. It is supported
by Apple Computer, Thinking Machines and Dow Jones.
WAN (Wide-Area Network)
A network spanning a large geographic area. (See LAN,
MAN.)
WebPhone
The use of the TCP/IP Protocol, usually over a high bandwidth Ethernet line,
to conduct voice communication using audio resources on a computer platform.
(also referred to as IP-Phone, EtherNet Phone)
Webmaster
The administrator responsible for the management (and often is the designer)
of a World Wide Web site.
Window
A rectangular area on a screen devoted to one particular application program.
Windows can overlap, and a user can move windows on top of other windows.
Workflow
A class of groupware software that automates daily routine operations of
a group in an organization.
Workstation
Single-user microcomputer which is normally part of a network that is capable
of high-performance and high-resolution sophisticated graphics.
WORM (Write Once Read Many)
A compact disk optical storage technology that enables data to be written
permanently to the optical platter. Data can be accessed repeatedly but
not overwritten.
WWW (World Wide Web)
The World Wide Web (the Web) is a distributed information retrieval system
on the Internet. Information is presented in hypertext objects using HTML
links to other Web servers or information pages. The information pages are
specified as URLs. The Web originated from the CERN high-energy physics
laboratories in Geneva, Switzerland. A client application is required, like
Mosaic, for browsing information on Web servers.
WYSIWYG (What You See Is What You Get)
A representation of data on a monitor such that when printed, it is an exact
facsimile of what appeared on the screen.
X Window System
Distributed, network-transparent, device-independent, multitasking windowing
and graphics system originally developed by MIT for communication between
X terminals and Unix workstations.
X11R5 (X Window System Release 5)
Version 11, release 5 of the X protocol, it is a hierarchial windowing system
developed at MIT that is network-transparent and architecture-independent.
X11R6 (X Window System Release 6)
This is Version 11, release 6 of the X protocol, and is the latest version
of the X Window protocol. (See X11R5.)
X.25
An established CCITT standard that defines the packet format for data transfers
in a public data network. Frame relay is similar but requires less control
information in each packet. Many establishments have X.25 networks in place
that provide remote terminal access. These networks can be used for other
types of data, including IP, DECnet and XNS.
X.400
A CCITT recommendation specifying an OSI standard for electronic mail transfer.
X/Open
The X/Open Company, Ltd. is an international organization promoting open,
multivendor application environments. It is, perhaps, best known for its
XPG. Recently Novell transferred ownership of the Unix trademark from USL
to X/Open. X/Open is one of the constituent organizations of The Open Group.
XMODEM
One of the original file transfer protocols that uses 128-byte packets.
XPG (X/Open Portability Guide)
A comprehensive set of voluntary APIs, protocols and other specifications
designed to promote open, interoperable computing. XPG4 is the current version
of this multivolume document.
YMODEM
An file transfer protocol that improved upon XMODEM and uses 1-kb packets.
(See ZMODEM.)
ZMODEM
A file-transfer protocol that improved upon YMODEM. When a ZMODEM file transfer
fails, the retransmission can pick up with the last successfully transferred
packet, rather than needing to retransmit the entire file.