10Base-2

A specification from the Institute of Electrical and Electronics Engineers for local-area network (LAN) cable and related equipment. 10Base-2 LANs transmit data at 10 megabits per second over thin Ethernet coaxial cabling spanning distances of up to 185 meters.

10Base-5

A local-area network (LAN) cable specification from the Institute of Electrical and Electronics Engineers. 10Base-5 LANs transmit data at 10 megabits per second over thick Ethernet coaxial cabling spanning distances of up to 500 meters.

10Base-F

A local-area network (LAN) physical-media specification from the Institute of Electrical and Electronics Engineers. 10Base-F LANs transmit data at 10 megabits per second over fiber-optic cable.

10Base-FL

A version of the 10Base-F specification supporting fiber-optic links (asynchronous connections linked by Ethernet repeaters). See 10Base-F.

10Base-T

A broadly used standard for Ethernet local-area network (LAN) wiring and related equipment. As specified by the Institute of Electrical and Electronics Engineers, 10Base-T LANs transmit data at 10 megabits per second over unshielded twisted-pair (UTP) wires (similar to the wiring commonly used for indoor phone lines). See Ethernet and UTP.

10Base-x series

A series of Institute of Electrical and Electronics Engineers (IEEE) specifications for Ethernet local-area network (LAN) cabling and related equipment, supporting speeds of up to 10 megabits per second (Mbps). Several common standards in this series are defined in separate entries (see 10Base-2, 10Base-5, 10Base-F, 10Base-FL and 10Base-T). The "10Base" prefix stands for "10 Mbps baseband" (see baseband); similar IEEE specifications for faster LANs use "100Base" and "1000Base" prefixes (see 100Base-x series and 1000Base-x series). The letter or numeral at the end of each specification name denotes the type of cable — "F" for fiber, "T" for twisted-pair, and numerals for various types of coaxial cable. See Ethernet.

100Base-F

A physical-media specification from the Institute for Electrical and Electronics Engineers, supporting Fast Ethernet local-area networks operating at 100 megabits per second over fiber-optic cable. See Fast Ethernet and fiber-optic.

100Base-FX

A version of the 100Base-F fiber-optic cable standard supporting half- and full-duplex operation. See 100Base-F.

100Base-T

A widely used standard for Fast Ethernet local-area network (LAN) wiring and related equipment. As specified by the Institute of Electrical and Electronics Engineers, 100Base-T LANs transmit data at 100 megabits per second over unshielded twisted-pair (UTP) copper cable. See Fast Ethernet and UTP.

100Base-TX

A version of the 100Base-T specification supporting both full-duplex and half-duplex transmission over two pairs of unshielded twisted-pair wires. See 100Base-T.

100Base-x series

A series of Institute of Electrical and Electronics Engineers (IEEE) specifications for Fast Ethernet local-area network (LAN) cabling and related equipment (see Fast Ethernet). Several common standards in this series are defined in separate entries (see 100Base-F, 100Base-FX, 100Base-T and 100Base-TX). These specifications are similar to those of the IEEE's 10Base-x series, but are designed for higher-speed transmission — up to 100 megabits per second (Mbps), rather than 10 Mbps (see 10Base-x series).

100VG-AnyLAN

An Institute for Electrical and Electronics Engineers (IEEE) standard for Ethernet and token ring local-area networks (LANs) transmitting at 100 megabit per second. (Originally dubbed "100Base-VG" as an IEEE Ethernet specification, it was renamed after token ring compatibility was added). In the 1990s, 100VG-AnyLAN was promoted heavily by Hewlett-Packard, among other vendors, as a technically superior LAN alternative to 100Base-T with Fast Ethernet, but it ultimately failed to win out in the marketplace. See 100Base-T and Fast Ethernet.

1000Base-LX

An physical network specification for long-wavelength laser transmission over fiber-optic cable, defined by the Institute for Electrical and Electronics Engineers. 1000Base-LX supports Ethernet transmission at 1,000 megabits per second over links up to 10 kilometers long, depending on the type of cable used. See Gigabit Ethernet.

1000Base-SX

A physical network standard for short-wavelength laser transmission over fiber-optic cable, defined by the Institute for Electrical and Electronics Engineers. 1000Base-SX supports Ethernet transmission at 1,000 megabits per second over links up to 500 meters long, depending on the type of fiber-optic cable used. See Gigabit Ethernet.

1000Base-T

An Institute for Electrical and Electronics Engineers standard for copper cabling and related equipment used in Gigabit Ethernet networks. 1000Base-T supports transmission at 1,000 megabits per second over unshielded twisted pair (UTP) cable. See UTP and Gigabit Ethernet.

1000Base-x

A series of Gigabit Ethernet network cable and equipment specifications from Institute for Electrical and Electronics Engineers (IEEE). For definitions of some of the better-known standards in this series, see 1000Base-LX, 1000Base-SX and 1000Base-T. These standards are similar to those of the IEEE's 10Base-x and 100Base-x series, but support data transmission at higher speeds — up to 1,000

megabits per second. See 10Base-x series, 100Base-x series and Gigabit Ethernet.

1394

A high speed serial bus specification from the Institute of Electrical and Electronics Engineers. See FireWire.

23B+D

An abbreviation for the Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI), composed of 23 bearer (B) channels and one data (D) channel. See ISDN and PRI.

24x7 (24 hours a day, seven days a week)

Continuous, round-the clock availability of a system or service.

2B+D

An abbreviation for the ISDN Basic Rate Interface (BRI), composed of two bearer (B) channels and one data (D) channel. See ISDN and BRI.

2PC (two-phase commit)

A method for coordinating a single transaction across two or more database management systems (DBMSs) or other resource managers. 2PC guarantees the logical integrity of data by ensuring that transaction updates are either finalized in all participating databases or fully backed out of all of them (that is, the update occurs "everywhere or nowhere"). 2PC is a required component of distributed databases, and is implemented in transaction management software that may be part of a DBMS, online transaction processing (OLTP) monitor or front-end application tool. See DBMS and OLTP.

3270

An interactive communications terminal used to communicate with an IBM mainframe or compatible system.

3380

An IBM direct-access storage device family introduced in 1980.

3390

An IBM family of storage products introduced in 1989.

3480

A half-inch tape cartridge format introduced by IBM in 1984.

3990

An IBM storage controller family introduced in 1987, supporting a wide range of devices, including 3380, 3390 and Random Access Method of Accounting and Control (RAMAC) systems. See 3380, 3390 and RAMAC.

3-D visualization

The use of interactive graphics to represent and manipulate high-volume, multidimensional data as graphical objects with a wide range of characteristics (including x/y/z axes, size, color, shape or movement).

3-D Web

Web site technology that provides a virtual, three-dimensional "space" for visitors to explore (for example, through the use of Virtual Reality Modeling Language; see VRML).

3G (third generation)

The term used to refer to the next generation of wireless communications technology, the "first generation" having been analog cellular, and the "second generation" being today's digital cellular networks. An initiative of the International Telecommunication Union and regional standards bodies, 3G aims to provide universal, high-speed (up to four megabits per second), high-bandwidth wireless services supporting a variety of advanced applications. See UMTS, IMT-2000 and EDGE.

3GPP (3rd Generation Partnership Project)

A collaboration agreement, established in 1998 among several telecommunications standards bodies, to produce a series of technical specifications and standards for third-generation (3G) wireless communications. See 3G.

3GL (third-generation language)

A high-level programming language — such as FORTRAN, COBOL, BASIC or C — that compiles to machine language.

3PL (third-party logistics)

A type of service provider that offers advanced logistics services, such as transportation management, inventory maintenance and logistical modeling.

3rd Generation Partnership Project (see 3GPP)

4GL (fourth-generation language)

A high-level language suitable for end-user or programmer data access and capable of reasonably complex data manipulation. A common example is Microsoft's Visual Basic. 4GLs includes two categories of software development tools: application generators for production applications, and information generators for decision support applications. 4GLs are relatively nonprocedural and easier to use than third-generation languages (3GLs), but are less powerful and more wasteful of computer resources. See 3GL.

802.1d

An Institute of Electrical and Electronics Engineers specification for local-area network spanning trees. See spanning tree.

802.1p

An Institute of Electrical and Electronics Engineers specification for priority queues within local-area networks.

802.1q

A virtual local-area network (VLAN) specification from the Institute of Electrical and Electronics Engineers. See VLAN.

802.1x

A port-based authentication protocol from the Institute of Electrical and Electronics Engineers.

802.11

A series of standards issued by the Institute of Electrical and Electronics Engineers for wireless local-area networks (WLANs). Various specifications cover WLAN transmission speeds from one megabit per second (Mbps) to 54 Mbps. There are three main physical-layer standards — see 802.11a, 802.11b and 802.11g.

802.11a

An Institute of Electrical and Electronics Engineers standard for the physical layer of wireless local-area networks (WLANs) operating in the five-gigahertz radio band. It has eight radio channels, each with a maximum link rate of 54 megabits per second; however, maximum user throughput will be about half this, and the throughput is shared by all users of the same radio channel. Frequency bands allowed for 802.11a (also called Wi-Fi5) differ in different parts of the world. See Wi-Fi5 and WLAN.

802.11b

A standard for the physical layer of wireless local-area networks (WLANs) operating at 2.4 gigahertz, from the Institute of Electrical and Electronics Engineers. Also called Wi-Fi, 802.11b specifies three radio channels, each with a maximum link rate of 11 megabits per second; however, maximum user throughput will be about half this, and the throughput is shared by all users of the same radio channel. See Wi-Fi and WLAN.

802.11g

An Institute of Electrical and Electronics Engineers physical-layer standard for wireless local-area networks operating at 2.4 gigahertz. It provides three available radio channels, each with a maximum link rate of 54 megabits per second. Support for complementary-code-keying modulation makes 802.11g backwardly compatible with 802.11b. The addition of further modulation schemes, such as orthogonal frequency division multiplexing (see OFDM), achieves higher link rates. See 802.11b and OFDM.

802.12

A competing standard to the Institute of Electrical and Electronics Engineers' (IEEE's) more widespread Ethernet (802.3) specification for local-area networks. Introduced in the 1990s in conjunction with the 100VG-AnyLAN standard, IEEE 802.12 networks use a "demand priority" access control mechanism, and can transport both Ethernet and token ring data frames. See 100VG-AnyLAN.

802.15

A Institute of Electrical and Electronics Engineers working group addressing standardization of wireless personal-area networks (PANs). See PAN.

802.15.4

A draft standard for low-data-rate, low-power-consumption wireless networking in the 2.4-gigahertz radio band. With data rates of less than 220 kilobits per second over 75 meters, 802.15.4 (dubbed "ZigBee" by the vendor group that promotes it) is suitable for many automation and remote-control applications. (See ZigBee and ZigBee Alliance.)

802.3

A protocol specification for Ethernet local-area networks (LANs) from the Institute of Electrical and Electronics Engineers (IEEE). 802.3 and the IEEE's 10Base-x series of cable specifications are the dominant standards used in today's LANs operating at 10 megabits per second (see 10Base-x series). Several extensions to the 802.3 standard support higher data rates (see 802.3u, 802.3z and 802.3ae).

802.3ae

An extension of the Institute of Electrical and Electronics Engineers' (IEEE's) 802.3 Ethernet network protocol specification. IEEE 802.3ae, also known as 10-Gigabit Ethernet, supports data rates of 10 gigabits per second. See 802.3.

802.3u

An extension of the Institute of Electrical and Electronics Engineers' (IEEE's) 802.3 Ethernet network protocol specification. IEEE 802.3u is also known as Fast Ethernet because it supports higher data rates than 802.3 — 100 megabits per second (Mbps) instead of 10 Mbps. See 802.3 and Fast Ethernet.

802.3z

An extension of the Institute of Electrical and Electronics Engineers' (IEEE's) 802.3 Ethernet network protocol specification. IEEE 802.3z, also known as Gigabit Ethernet, supports data transmission rates up to one gigabit per second. See 802.3 and Gigabit Ethernet.

802.5

A token ring network protocol specification from the Institute for Electrical and Electronics Engineers. See token ring.

802.6

A metropolitan-area network (MAN) specification from the Institute for Electrical and Electronics Engineers. See MAN.

80x86

A family of Intel microprocessors once used in IBM-compatible PCs and workstations. It includes the 80286, 80386 and 80486. The first Pentium processors are members of the same family, but the numerical designations have been dropped. See Pentium.

A

A2A (application-to-application)

An approach to enterprise application integration that provides visibility into internal systems, so that these systems can share information or business processes.

A3 (Adaptive Application Architecture)

A Gartner reference model for an application platform that can adapt to a variety device types and networks (notably mobile devices and wireless data transmission), and that can support all types of data transactions. The A3 goes beyond the limitations of network- and device-specific wireless platforms to provide a more comprehensive model suitable to the new challenges of network computing (for example, maintaining multiple, changing devices, unstable and mixed-media content, and multiple networks). The A3 comprises three logical components:

• Link layer — the elements managing the link (i.e., the network transport), such as session management, synchronization, security, device discovery and location awareness.
• Transformation platform — the elements handling the transformation of the data stream, including filtering, selection, ordering and formatting.
• Profile management — the management of persistent data that supports the overall interaction.

Because it abstracts across multiple device types and media, the A3 is a key element in the evolution of the Supranet (see Supranet).

AA (see application architecture and automated attendant)

AAC (ATM access concentrator)

A device used to concentrate a variety of services (such as frame relay, Internet Protocol and video) over a single asynchronous transfer mode (ATM) network access connection. See ATM.

AAL (ATM adaptation layer)

The asynchronous transfer mode (ATM) layer where non-ATM data is converted to ATM format. The AAL serves as the "glue" that connects traditional packet and frame structures with short, fixed-length ATM cells. It forms the top layer of the ATM version of the Broadband Integrated Services Digital Network (B-ISDN) protocol stack. See ATM and B-ISDN.

ABAP (Advanced Business Application Programming)

The core development tool in SAP's R/3 system.

ABC (activity-based costing)

An approach to understanding where and why costs are incurred within an enterprise. It provides the information for activity-based management, which focuses on the decisions and actions needed to reduce costs and increase revenue. ABC differs from traditional cost accounting in explicitly recognizing that not all cost objects place an equal demand on support resources.

ABEND (abnormal end)

A type of system error in which a task or program fails to execute properly (i.e., "abnormally ends"). The term is also used as the name for a type of error message that indicates such a failure has occurred.

ABI (application binary interface)

A set of specifications that enables an application written for one target operating system (OS) and hardware platform to run on a different OS and platform, where the two hardware platforms share the same processor type. ABIs enable compatibility only among products built on the same microprocessor architectures.

ABM (activity-based management)

The use of activity-based costing (ABC) principles in the ongoing management of costs and resources. See ABC.

ABR (available bit rate)

An asynchronous transfer mode (ATM) service category. ABR service is conceptually similar to that of a frame relay network — a minimal cell rate is guaranteed, and bursts can be supported if the network resources allow it. See ATM.

AC (alternating current)

A type of power supply in which the current periodically reverses direction, as distinguished from a direct current (see DC).

ACA (Australian Communications Authority)

The Australian government body that regulates the nation's communications industries.

access charge

The charge assessed to communications users for access to the local or regional exchange to send or receive calls. It also includes access to specialized telecommunications services and access to the customer's local access and transport area.

access code

The digit or digits that a user must dial to be connected to an outgoing trunk facility.

access control

Functions and administrative tasks related to system or network access, including user identification and access recording.

access line

The connection to the customer's local telephone company for origination of local and long-distance calls. Also known as a local loop or trunk.

access method

1. The portion of a computer's operating system responsible for formatting data sets and their direction to specific storage devices. Examples from the mainframe world include Virtual Storage Access Method (VSAM) and Indexed Sequential Access Method (ISAM). See VSAM and ISAM.
2. In local-area networks (LANs), the technique or program code used to arbitrate stations' use of the LAN by granting access selectively to individual stations. Examples include carrier sense multiple access with collision detection (CSMA/CD) and token passing. See CSMA/CD and token passing.

access point

The basic building block of a wireless local-area network infrastructure. Access points attach to a wired backbone and provide wireless connectivity to all devices within range. In a roaming infrastructure, as devices move out of the range of one access point, they move into the range of another.

access router

An access device with built-in basic routing protocol support, specifically designed to allow remote network access to corporate backbone networks. Access routers are not designed to replace backbone routers or to build backbone networks. They usually have limited protocols, few ports and low speed.

accounting rate

The charge per traffic unit — a unit of time or information content — covering communications between zones controlled by different telecommunications authorities. Accounting rates are used to establish international tariffs.

ACD (automatic call distributor)

A specialized phone system that handles many incoming calls. ACDs are used for a variety of order-taking functions, such as calls to help desks or dispatching of service technicians. They are designed to distribute a large volume of incoming calls uniformly to operators or agents (for example, for airline reservations).

ACE (Advanced CMOS-ECL)

A high-end processor technology introduced by Hitachi in the 1990s.

ACF (Advanced Communications Function)

A family of IBM communications programs that handle tasks such as resource sharing and distribution of functions. They include ACF/Virtual Telecommunications Access Method (ACF/VTAM) and ACF/Network Control Program (ACF/NCP). IBM eventually dropped the "ACF/" prefix from many of these program names; for example ACF/VTAM is now known simply as "VTAM."

ACF2 (Access Control Facility 2)

A host-based security subsystem from Computer Associates; also known as CAACF2.

ACH (automated clearinghouse)

A type of funds transfer network that processes debit and credit transactions between accounts from participating financial institutions.

ACID (atomicity, consistency, isolation, durability)

Four well-established tests for verifying the integrity of business transactions in a data-processing environment.

ACL (access control list)

Manages users and their access to files and directories. Access control requires linking users with content. User information is stored in a directory, and content is referenced in ACLs.

ACM (Association for Computing Machinery)

An educational and scientific computing society, founded in 1947, whose membership today includes more than 80,000 computing professionals and students worldwide.

ACMS (Application Control and Management System)

A transaction-processing monitor from Compaq (now part of Hewlett-Packard); originally a product of Digital Equipment, which Compaq acquired in 1998.

ACP (array control processor)

A type of processor used in storage systems.

ACPI (Advanced Configuration and Power Interface)

A standard developed by Intel, Microsoft and Toshiba to improve PC power management and plug-and-play capabilities.

A-CPR (ambulatory computer-based patient record)

A computer-based patient record (CPR) used exclusively in the ambulatory/outpatient care delivery environments of healthcare. See CPR.

ACR (attenuation-to-crosstalk ratio)

A measure of signal quality in network cabling.

Acrobat

A product from Adobe Systems used to display documents in digital form as they appeared in their original, paper format. As an Internet plug-in, it is often used display documents, such as brochures, on the Web.

ACS (Affiliated Computer Services)

A business process and IT outsourcing provider headquartered in Dallas, Texas.

ACSLS (Automated Cartridge System Library Software)

A Unix-based tape-library-sharing system from Storage Technology.

Active Directory

The directory service portion of the Windows 2000 operating system. Active Directory manages the identities and relationships of the distributed resources that make up a network environment. It stores information about network-based entities (such as applications, files, printers and people) and provides a consistent way to name, describe, locate, access, manage and secure information about these resources.

ActiveX

A Microsoft technology that facilitates various Internet applications, and therefore extends and enhances the functionality of Microsoft's Internet Explorer browser. Like Java, ActiveX enables the development of interactive content. When an ActiveXaware browser encounters a Web page that includes an unfamiliar feature, it automatically installs the appropriate applications so the feature can be used.

actuator

A disk drive mechanism. The actuator positions the disk read-write head over the selected track.

AD (application development)

The function of creating applications for an enterprise. The term refers not simply to programming, but to the larger overall process of defining application requirements, planning the application structure, developing the code, monitoring development progress and testing results.

A/D (analog-to-digital)

The term used to describe a type of converter used to bridge analog and digital circuitry. A/D converters can be either stand-alone microcomponents, or included in the functionality embedded in certain advanced processor types.

adapter

A type of middleware that combines design tools and runtime software to act as "glue" to link applications to the enterprise nervous system (ENS). Adapters perform a variety of tasks, including recognizing events, collecting and transforming data, and exchanging data with the ENS. They also handle exceptions and can often dynamically accommodate new revisions of back-end applications. See middleware and ENS.

adaptive routing

Routing that automatically adjusts to network changes, such shifts in network traffic, to find the most efficient path for transmission.

ADC (analog-to-digital converter)

Component used to bridge the digital and analog circuitry contained in certain advanced integrated circuits. Also known as an A/D converter (see A/D).

ADC (automated data collection)

The automated conversion of disparate types of information into computer records. ADC devices and technologies include bar code systems, optical character recognition and speech recognition.

address

1. Coded representation of the origin or destination of data on the Internet or another type of network. Each Web site, or each terminal on a communications line, has a unique address.
2. In software, a location in memory that can be specifically referred to in a program.

address translation

The process of changing the identifier associated with an item of data, or an instruction, to the actual location in main storage where it is held.

ADE (application development environment)

An product that offers a range of tools or features (for example, for programming, interface development and testing) to provide a complete "environment" for developing applications.

ADF (Application Development Facility)

An IBM program for developing Information Management System (IMS) applications. See IMS.

ADF (automated document factory)

Gartner's term for an architecture and set of processes to manage the creation and delivery of mission-critical, high-volume digital documents. The ADF applies factory production concepts to the document production — raw materials, including data and preparation instructions, enter the ADF, where they are transformed into digital documents and prepared for delivery.

ADMF (Asynchronous Data Mover Facility)

A IBM mainframe feature designed to enhance system performance in data moves between central and expanded storage.

ADO (ActiveX Data Objects)

A high-level data access object model introduced by Microsoft in 1996.

ADP (Automatic Data Processing)

A check-processing and payroll services company based in Roseland, New Jersey.

ADPCM (adaptive differential pulse code modulation)

A speech-coding method that calculates the difference between two consecutive speech samples in standard pulse code modulation (PCM) coded telecommunications voice signals. This calculation is encoded using an adaptive filter and, as a result, allows analog voice signals to be carried on a 32 Kbps digital channel in half the space PCM uses.

ADSI (Active Directory Services Interface)

A Microsoft Active Directory feature that enables Windows 2000 applications to interact with other directory services — such as NetWare or Lightweight Directory Access Protocol (LDAP) directories — without the need to know the details of the underlying protocols. See Active Directory and LDAP.

ADSI (Analog Display Services Interface)

A protocol developed by Bellcore in the 1990s. ADSI enables information communicated over an analog phone line to be displayed on the screen of an ADSI-compatible device.

ADSL (asymmetric digital subscriber line)

ADSL allows cable TV, video, telephony and other multimedia services to be sent over voice-grade twisted-pair cable carrying from 1.5 megabits per second (Mbps) to 8 Mbps downstream, and from 16 kilobits per second (Kbps) to 640 Kbps upstream (hence the designation "asymmetric"), over distances ranging from two to six kilometers without the use of repeaters. ADSL uses adaptive digital filtering, which adjusts to compensate for noise and other problems on the line.

ADSM (ADSTAR Distributed Storage Manager)

An IBM software product for managing storage, data access and backup across multivendor enterprisewide networks. Following IBM's acquisition of Tivoli Systems in the 1996, ADSM was taken over by IBM Tivoli and eventually renamed Tivoli Storage Manager.

ADSTAR (Automated Document Storage and Retrieval)

IBM's name for its storage products business in the 1990s.

ADT (admission, discharge and transfer)

A category of hospital software. An ADT system records admissions to, discharges from and transfers within a hospital, and maintains the hospital census.

advanced technology

A technology that is still immature but promises to deliver significant value, or that has some technical maturity but still has relatively few users; also known as an "emerging technology." Current examples include artificial intelligence, biometrics, e-tags, grid computing and wearable computers.

ADW (Active Data Warehouse)

A relational database from i2 Technologies. The ADW serves as an operational data store for the data used in systems such as i2's Supply Chain Planner tool.

AEC (architecture, engineering and construction)

A market category for computer-aided design and engineering applications.

AFC (antiferromagnetically coupled)

A type of storage media that uses an advanced magnetic coating expected to dramatically increase hard disk drive (HDD) capacity. IBM shipped the first AVC-based storage products in 2001.

affiliate

An enterprise that sells products of other manufacturers or retailers (i.e., sponsoring merchants) on its Web site. Users select products at the affiliate Web site, but the sale is actually transacted at the sponsoring merchant's site. Affiliates are similar in concept to industry-based manufacturing representatives that sell multiple manufacturers' product lines.

AFP (Advanced Function Printing)

An IBM all-points-addressable enterprisewide print architecture.

agent

Software that acts as an intermediary for a person by performing an activity. Intelligent agents can "learn" an individual's preferences and act in the person's best interest. For example, an agent for a purchasing manager could learn corporate specifications, determine when inventory is low, search the Internet for the lowest-cost supplier, and even negotiate and complete transactions. See intelligent agent.

aggregator

An entity that enables buyers within a market to select among competitors by aggregating information about the market and its suppliers and providing this information via a Web site. Aggregators may provide decision-support applications that integrate supplier information with third-party information and with user requirements or preferences to allow users to differentiate the services and features of various competitors. Content aggregators aggregate information and match it to user preferences. These preferences may be declared actively (that is, if the user explicitly specifies them) or passively (for example, the software discerns preferences from patterns of user behavior or interest).

AGP (Accelerated Graphics Port)

An Intel technology for desktop systems. It increases system performance by offloading graphic requirements from the system bus to a bus dedicated to video processing.

AHP (analytical hierarchy process)

A process that uses hierarchical decomposition to deal with complex information in multicriterion decision making, such as information technology vendor and product evaluation. It consists of three steps:

1. Developing the hierarchy of attributes germane to the selection of the IT vendor.
2. Identifying the relative importance of the attributes.
3. Scoring the alternatives' relative performance on each element of the hierarchy.

Developed by Thomas Saaty while he was teaching at the University of Pennsylvania's Wharton School of Business, the AHP is recognized as the leading theory in multicriterion decision making.

AI (artificial intelligence)

A wide-ranging discipline of computer science that seeks to make computers become "intelligent" by enabling them to employ processes similar to those used by the human mind. The term was coined by John McCarthy of the Massachusetts Institute of Technology in 1956. AI involves the capability of a machine to learn (to remember results produced on a previous trial and to modify the operation accordingly in subsequent trials) or to reason (to analyze the results produced in similar operations and select the most favorable outcome). Today's AI applications include voice recognition, robotics, neural nets and expert systems.

AIAG (Automotive Industry Action Group)

An association of automotive companies which has defined a number of standards, including the E-5 standard for sending e-commerce transactions over the Automotive Network Exchange, an IP-based commerce network. The group's electronic data interchange (EDI) standards work includes implementation guides for X12 transactions, and the contribution of content to the AS2 specification. See EDI and AS2.

AICPA (American Institute of Certified Public Accountants)

A U.S. association for accounting professionals. In the United States, the AICPA is the primary governing body for the interpretation of accounting rules. This group publishes guidelines and rulings designed to ensure consistent treatment of complex accounting issues, such as software revenue recognition.

AIIM (Association for Information and Image Management)

A Maryland-based organization dedicated to promoting development of systems that store, retrieve and manage document images.

AIM (AOL Instant Messenger)

The instant messaging (IM) technology offered in America Online's (AOL's) Internet service. AIM is among the most widely used IM services, with more than 60 million registered users worldwide.

AIN (Advanced Intelligent Network)

Introduced by AT&T Network Systems in 1991, AIN enables service providers to define, test and introduce new multimedia messaging, personal-communication and cell-routing services. See intelligent network.

AIT (Advanced Intelligent Tape)

An eight-millimeter helical-scan tape drive designed and manufactured by Sony. Sony has differentiated its AIT drive from other 8-millimeter tape drives with a unique media feature on the tape cartridge called memory in cassette (MIC). See MIC.

AIX (Advanced Interactive Executive)

A Unix-based operating system from IBM.

A/L (Archive Link)

An interface that enables enterprises to link traditional storage archives with SAP R/3. A/L is the product of a partnership between SAP and iXOS Software.

alert

A message displayed by an application or operating system to notify the user of certain conditions.

algorithm

A process for calculations involving the manipulation of numbers.

ALL-IN-1

A VAX/VMS-based office information system that was a dominant player in corporate messaging in the late 1980s, from Digital Equipment (acquired in 1998 by Compaq Computer, which in turn was acquired by Hewlett-Packard in 2002).

Alpha

A 64-bit reduced instruction set computing (RISC) microprocessor from Compaq (now part of Hewlett-Packard), which acquired the technology with its 1998 purchase of Digital Equipment.

alternate routing

Method of routing wherein a secondary communications path is used if the usual one is not available (also called "alternative routing").

alternating current (see AC) alternative routing (see alternate routing) ALU (arithmetic logic unit)

A central processing unit's (CPU's) core element, which carries out arithmetic computations. See CPU.

AM (amplitude modulation)

A means of modulating a wave signal to carry information. With AM, the amplitude of the carrier wave is varied in accordance with the information to be transmitted. See FM.

AMA (automatic message accounting)

A function that automatically documents billing data related to subscriber-dialed long-distance calls.

ambient noise

Communications interference present in a signal path at all times.

mbulatory suite

A healthcare application suite consisting of practice management, contract management and ambulatory computer-based patient record (A-CPR) application components. See A-CPR.

AMD (Advanced Micro Devices)

A microprocessor manufacturer headquartered in Sunnyvale, California.

AME (Advanced Metal Evaporated)

A media formulation manufactured by Sony for use in its consumer and computer product lines.

AMI (alternate mark inversion)

A digital signaling method in which the signal carrying the binary value alternates between positive and negative polarities; zero and one values are represented by the signal amplitude at either polarity, while no-value "spaces" are at zero amplitude. Also called bipolar.

AMIA (American Medical Informatics Association)

A not-for-profit organization dedicated to the development and application of medical informatics in the support of patient care, teaching, research and healthcare administration. The AMIA serves as an authoritative body in the field of medical informatics and represents the United States in the informational arena of medical systems and informatics in international forums.

AMIS (Audio Messaging Interchange Specification)

An enhanced key system feature for voice/call processing that enables enterprise locations to transfer and forward voice messages between systems. It is a voice processing standard that specifies the procedures to network voice processing systems, regardless of who manufactures the system.

AMO (application management outsourcing)

The ongoing maintenance, management, conversion, enhancement and support of an application portfolio by an external company. AMO, a subset of application outsourcing (see separate entry), includes changes that generally take less than some predefined time to implement (for example, 10 days or 30 days). Examples of maintenance include regulatory changes, software upgrades, new release installations and "fix it if it breaks" troubleshooting. AMO may involve the transfer of people and application software to the vendor.

amplifier

An electronic component that boosts the strength or amplitude of a transmitted, usually analog, signal; functionally equivalent to a repeater in digital transmissions.

amplitude

A departure of the value of a wave or alternating current from its average value.

AMPS (advanced mobile phone service)

An AT&T-developed analog cellular radio technology, operating in the 800 megahertz frequency band.

AMS (American Management Systems)

A business and IT consulting firm headquartered in Fairfax, Virginia.

AMS (Application Management Specification)

A set of application programming interfaces that enable the consistent definition of applications for deployment and management, from IBM's Tivoli subsidiary.

analog Information presented in the form of a continuously varying signal (see analog signal) — in contrast to digital transmission, where information is conveyed in the form of discrete, digital units (see digital).

analog signal

A signal in the form of a continuous, wave-like pattern, with variations in the signal's properties (such as voltage) reflecting variations in the information carried (such as loudness of the human voice). An analog signal conveys information by modulating (i.e., varying) the frequency, amplitude or phase of the signal's carrier wave. Analog signaling is used in the public switched telephone network (PSTN) and other audio and radio frequency facilities, such as broadcasting. A digital baseband signal generated by a data network must be converted to analog form to be transmitted over an analog facility, such as a voice grade telephone line. This process is performed by a modulation device, such as a modem. See modem, modulation and PSTN.

analog transmission

Transmission of a continuously variable signal, as opposed to a discretely variable (e.g., digital) one. See analog signal.

ANDF (Architecture-Neutral Distribution Format)

The Open Group's format enabling distribution of a single version of an application to computers with different hardware and software architectures. Launched in the 1990s, ANDF failed to achieve widespread adoption.

ANI (automatic number identification)

A series of digits, in either analog or digital form, which tells a user the originating number of the incoming phone call. Caller ID is the most familiar form of ANI.

ANOVA (analysis of variance)

A form of statistical analysis.

ANSI (American National Standards Institute)

In the United States, ANSI serves as a quasi-national standards organization. It provides "area charters" for groups that establish standards in specific fields. These groups include the Institute of Electrical and Electronics Engineers (IEEE) and the Electronic Industries Alliance (EIA). ANSI is unique among the world's standards groups as a nongovernmental body granted the sole vote for the United States in the International Organization for Standardization (ISO). This status is part of the reason ANSI bends over backward to limit its role to that of facilitator, or catalyst, in the production of standards. See IEEE, EIA and ISO.

antenna

A device used to transmit or receive radio waves. The physical design of the antenna determines the frequency range of transmission and reception.

ANX (Automotive Network Exchange)

Established by the Automotive Industry Action Group to offer extranet-based applications to suppliers of Chrysler, Ford and General Motors.

AOA (angle of arrival)

Based on triangulation, a method of processing cellular phone signals, AOA allows the physical position of switched-on wireless devices to be located. The position is determined by comparing the AOA of the existing reverse control channel at various cell sites.

AOL (America Online)

A company (now a subsidiary of Time Warner) that offers Web access, e-commerce and related Internet products and services. Founded in 1985 and headquartered in Dulles, Virginia, AOL initially offered limited, non-Web online services, but grew rapidly (to over 30 million subscribers) after making its services Web-based and aggressively marketing them as a simple, easy-to-use Internet access option for mass-market consumers. In 2000, AOL acquired media conglomerate Time Warner for over $300 million — at the time, the largest merger in U.S. corporate history.

Apache

An open-source Web server platform.

APACS (Association for Payment Clearing Services)

The organization that manages U.K. payment systems.

API (application programming interface)

A set of calling conventions that defines how a service is invoked through software. An API enables programs written by users or third parties to communicate with certain vendor-supplied software.

APO (Advanced Planner and Optimizer)

A supply-chain-planning suite from SAP.

APPC (Advanced Program-to-Program Communication)

The programming interface to LU 6.2, IBM's protocol for peer-to-peer program communication under Systems Network Architecture (SNA). See LU 6.2 and SNA.

Apple Computer

A computer hardware and software vendor based in Cupertino, California. Apple revolutionized the personal-computing business in the 1980s with the launch of the Macintosh computer and its user-friendly interface and operating system. Although Apple remains a strong competitor in some computer markets (such as the consumer, education, graphic arts and publishing segments), it is no longer a major player in the mainstream business PC market, which is now dominated by IBM-compatible PCs running Microsoft Windows.

AppleShare

An Apple Computer operating-system feature that enables the sharing of files and network services.

AppleTalk

A proprietary network protocol from Apple Computer. AppleTalk has become a legacy network environment, as Apple now recommends that Transmission Control Protocol/Internet Protocol (TCP/IP) be used to network Mac-based systems. See TCP/IP.

applet

A small program that runs within an application. Applets are commonly used to make otherwise static Web pages more interactive. Examples include animated graphics, games, configurable bar charts and scrolling messages. See Java applet.

appliance (see computing appliance)

applicant tracking system

An application used to track resumes and data on job applicants. Typically, these applications include matching features, which rank candidates by matching them to criteria specified in the requisition for an open position.

application

A specific use for a computer or program, such as for accounts payable or payroll. The term is commonly used in place of the terms "application program," "software" or "program." Examples of programs and software include pre-packaged productivity software (such as spreadsheets and word processors) and larger, customized packages designed for multiple users (such as e-mail and workgroup applications).

application architecture

An architecture that describes the layout of an application's deployment. This generally includes partitioned application logic and deployment to application server engines. Application architectures rely less on specific tool or language technology than on standardized middleware options, communications protocols, data gateways, and platform infrastructures such as Component Object Model (COM), JavaBeans and Common Object Request Broker Architecture (CORBA). The application architect is tasked with specifying the architecture and supporting the deployment implementation.

application database

The initial point of capture for much of the data that enters an enterprise. Application databases are accessed and updated by end users through online transaction processing (OLTP) applications. These databases tend to contain detailed and up-todate data; however, because OLTP applications normally support specific business processes, application databases tend to be process-specific, rather than enterprisewide, in nature. They may support some degree of data analysis, but this tends to be secondary to OLTP activity. An application database is often a source for refinement of data into one or several of the other database implementation styles, such as a data warehouse or operational data store (ODS). See database, data warehouse and ODS.

application generator

A type of fourth-generation language (4GL) development tool used to create production applications. See 4GL.

application hosting

A service in which a vendor will house shared or dedicated servers and applications for an enterprise at the provider's controlled facilities. The vendor is responsible for day-to-day operations and maintenance of the application. Application hosting is typically based on service arrangements in which vendors provide the hardware, software and networking infrastructure that enables enterprises to run applications externally by connecting electronically using a browser. A vendor may offer the services directly or, more commonly, through an arrangement with an application service provider (ASP). See hosting and ASP.

application integration

The process of enabling independently designed applications to work together. This can range from simple approaches — such as providing users with access to data and functionality from multiple applications through a single user interface — to more sophisticated approaches involving integration brokers or middleware. See integration broker and middleware.

application layer

The top layer of the Open Systems Interconnection (OSI) network model, offering an interface to, and largely defined by, the network user. See OSI.

application outsourcing

An outsourcing arrangement for a wide variety of application services including new development, legacy system maintenance, offshore programming, management of packaged applications and staff augmentation. While this form of outsourcing generally involves a transfer of staff, the use of the term has recently broadened to include arrangements where this is not the case, as in staff augmentation. It does not include system integration activities.

application portfolio

The group of applications used and maintained by an enterprise — whether internally developed or externally sourced.

application portfolio analysis

A tool to divide established and proposed applications into three categories — utility, enhancement and frontier — based on the degree to which they contribute to the enterprise's performance. The utility category is essential but does not enhance the enterprise's performance (e.g., payroll); the enhancement category contains applications that improve the enterprise's performance based on the use of established technology (e.g., documentation automation); and the frontier category is aimed at greatly improving enterprise performance (e.g., through aggressive use of rules-based decision support) but usually entails substantial risk. The management issues for each category are, respectively, cost, opportunity identification and innovation. The planning process should consider the best balance among the three categories to gain optimal future performance and the appropriate value from the application of IT.

application program

A software program that performs a specific task or function — as differentiated from supervisory program (i.e., an operating system or other type of system software). Application programs (generally known by the less formal term "applications") contain instructions that transfer control to the system software to perform input/output and other routine operations, working through an application programming interface.

application server

1. A hardware server designated to run applications (but not a database).
2. System software used to host the business logic tier of applications. In three-tier applications, the application server manages business logic and enables it to be accessed from the user interface tier. In a service-oriented architecture (SOA), an application server hosts the application services and also plays the role of a fundamental enabling technology. Transaction-processing monitors (TPMs) and object transaction monitors (OTMs) are examples of native application server products. See SOA, OTM and TPM.

application sharing

The ability of two or more network-connected participants to have simultaneous control over the content of a document running in an application (such as a word-processing or spreadsheet application). A component of data conferencing, application sharing enables users in different locations to collaborate on creating or editing documents.

APPN (Advanced Peer-to-Peer Networking)

An extension of IBM's Systems Network Architecture (SNA) that provides dynamic, multipath routing among computers in an SN