G

G2B (government-to-business)
Connecting or flowing between government and private-sector enterprises, typically through online or network-enabled channels.

G2C (government-to-constituent)
Connecting or flowing between governments and their constituents, typically through Internet or other network-enabled channels.

G2G (government-to-government)
Intergovernmental, typically with reference to Internet or other network-enabled interactions, communications or information sharing.

G2 (Generation 2)
IBM's second generation of 9672 mainframe models.

G3 (Generation 3)
IBM's third generation of 9672 mainframe models.

G4 (Generation 4)
IBM's fourth generation of 9672 mainframe models.

G5 (Generation 5)
IBM's fifth generation of 9672 mainframe models.

G6 (Generation 6)
IBM's sixth generation of 9672 mainframe models, introduced in May 1999.

G.7xx series
A series of International Telecommunication Union (ITU) standards for voice and data communications (see ITU). The series includes:

• G.703: Specifications for plesiochronous digital hierarchy (see PDH).

• G.709: Specifications for synchronous digital hierarchy (see SDH).

• G.711: Specifications for digital speech encoding based on a pulse code modulation (see PCM) digitizing algorithm using logarithmic encoding.

• G.721: Specifications for digital speech encoding based on an adaptive differential pulse code modulation (ADPCM) technique. See ADPCM.

• G.723: Specifications for the voice component of the H.323 videoconferencing suite (see H.x series).

• G.728: Specifications for digital speech encoding using low bit rates based on a sector generalization scheme (which yields lower sound quality than G.711).

GA (general availability)
The point at which a new product is available on the open market.

GaAs (gallium arsenide)
A chemical used in semiconductor manufacturing.

gain
Denotes an increase in signal power in transmission from one point to another, usually expressed in decibels.

gain sharing
Describes a contract that defines the vendor's contribution to the customer in terms of specific benefits to the customer's business. Such a contract also defines the payment the customer will make according to the vendor's performance in delivering these benefits. Gain-sharing contracts require the development of a delivery paradigm that links a customer's business metrics to a vendor's IT solution. Key elements of this paradigm include:

• Business metric definition and selection

• Client metric benchmarking

• Development of key performance indicators

• Investment options evaluation

• Gain-sharing contract development

• Financial engineering

• Delivery of services

• Re-evaluation and adjustment of metrics

gallium arsenide (see GaAs)

gateway

1. A computer that sits between different networks or applications. The gateway converts information, data or other communications from one protocol or format to another. A router may perform some of the functions of a gateway. An Internet gateway can transfer communications between an enterprise network and the Internet. Because enterprises often use protocols on their local-area networks that differ from those of the Internet, a gateway will often act as a protocol converter, enabling users to send and receive communications over the Internet.

2. A product or feature that uses proprietary techniques to link heterogeneous systems.

gateway server
A server designed to transform data streams to better match device capabilities. For example, Wireless Application Protocol gateway servers convert Hypertext Markup Language (HTML) to Wireless Markup Language for wireless devices, and a number of products can reformat HTML for devices such as mobile phones and personal digital assistants. Today, HTML-based gateway servers predominate. While HTML can be made aware of a unique device requesting content, more often "shadow" Web server applications are created to draw off and reformat the native content.

Gb (gigabit)
Approximately one billion bits of data (1,073,741,824, to be exact).

GB (gigabyte)
Approximately 1 billion bytes of data (actually 1,073,741,824 bytes).

Gbps (gigabits per second)
A measure of data transmission speed (see Gb).

GCOS (General Comprehensive Operating System)
A Groupe Bull mainframe operating system.

GCR (group code recording)
A tape drive format used in storage systems.

GDI (Graphics Device Interface)
A Microsoft print control interface. Under GDI, the page image is communicated to the printer in the native Windows format. The formatting is done on the computer, so the printer needs less onboard processing power and memory than with page description languages.

GDPS (Geographically Dispersed Parallel Sysplex)
An IBM mainframe feature for continuous availability and disaster recovery across multiple, geographically dispersed sites.

GEMMS (Global Enterprise Manufacturing Management System)
A process manufacturing product once offered by Datalogix (which was acquired by Oracle in 1997).

GEMS (Global Enterprise Management of Storage)
A family of storage management products from Legato Systems.

general availability (see GA)

General Inter-ORB Protocol (see GIOP)

general packet radio service (see GPRS)

General Security Services Application Programming Interface (see GSS-API)

Generation 2 (see G2)

Generation 3 (see G3)

Generation 4 (see G4)

Generation 5 (see G5)

Generation 6 (see G6)

Generation N (see GN)

genetic algorithm
An optimization technique that applies the principles of natural selection and genetics. A genetic algorithm generates option variations through random "mutation." Successful variations survive iterations of the algorithm. The technique is used to optimize plans, neural nets and other algorithms.

geocoding
Identifying narrow locations using postal codes or other identifiers for marketing, delivery or planning purposes.

Geographically Dispersed Parallel Sysplex (see GDPS)

geographic information system (see GIS)

GFLOPS (gigaFLOPS)
A measure of computing performance, equal to 1 billion floating-point operations per second (FLOPS). For example, 50 GFLOPS equals 50 billion FLOPS.

GHz (gigahertz)
A frequency unit equal to one billion cycles per second.

GIF (Graphics Interchange Format)
An integrated Web component of Hypertext Markup Language into which graphics files can be converted so that programs can recognize them.

gigabit (see Gb)

Gigabit Ethernet
The Institute of Electrical and Electronics Engineers standard (802.3z) for transmission of standard Ethernet traffic at one gigabit per second. See Ethernet, 802.3 and 802.3z.

Gigabit Switch Router (see GSR)

gigabyte (see GB)

gigaFLOPS (see GFLOPS)

gigahertz (see GHz)

gigaPOP
A point of presence (POP) capable of supporting multiple gigabit-per-second lines at once. A gigaPOP has lower-speed Internet Protocol (IP) routing capabilities at the fringes of the backbone networks, and an asynchronous transfer mode (ATM) switching core that can carry IP, X.25, frame relay and ATM traffic — eliminating the need for separate and costly networks to support different types of traffic.

GIOP (General Inter-ORB Protocol)
A protocol that defines a small set of messages and data formats. Part of the Common Object Request Broker Architecture (CORBA), GIOP enables a client-side object request broker (ORB) to forward object method invocations to another, server-side ORB and receive back replies and error messages. See CORBA and ORB.

GIS (geographic information system)
Computer-based technology composed of hardware, software and data used to capture, edit, display and analyze spatial information (that is, information tagged by location). GIS technology is used in many spatial-data applications, including marketing functions such as demographic analysis, and government functions such as zoning and census mapping.

GL (general ledger)
A permanent record of accounting transactions summarized according to an enterprise's accounting and organizational structure. A GL system is designed to summarize entries from subledger systems and produce financial statements and reports.

GLBA (Gramm-Leach-Bliley Act) — see FMA99

G.Lite
An International Telecommunication Union (ITU) specification (ITU G.992.2) for a reduced-speed, splitterless version of asymmetric digital subscriber line (see ADSL).

Global Enterprise Management of Storage (see GEMS)

Global Enterprise Manufacturing Management System (see GEMMS)

GlobalOne
A company that provides global voice and data communications services. Originally launched as a joint venture by Deutsche Telecom, France Telecom and Sprint in 1996, it was wholly taken over by France Telecom in 2000.

Global Navigational Satellite System (see GLONASS)

Global Network Services (see GNS)

Global Positioning System (see GPS)

Global Resource Serialization (see GRS)

global sourcing
A service delivery model in which work is performed by a virtual team, which may consist of personnel that are on-site, domestic, nearshore or offshore. See nearshore and offshore.

Global System for Mobile Communications (see GSM)

GLONASS (Global Navigational Satellite System)
A satellite-based geographic-location system run by the Russian government. See GPS.

GMLC (Graduated Monthly License Charge)
The traditional S/390 software pricing structure offered by IBM.

GN (Generation N)
A catch-all term encompassing IBM's various generations of 9672 mainframe models. See G2, G3, G4, G5 and G6.

GNS (Global Network Services)
An AT&T unit that provides various managed-networking, IP and network-outsourcing services.

GNU (GNU's Not Unix)
A project launched in 1984 to develop a free, complete Unix-like operating system. Variants of the GNU operating system (which use the kernel Linux) are now widely in use. Although these systems are often referred to as "Linux systems," they are more accurately termed "GNU/Linux systems."

GNU ZIP
GNU's compression utility for Unix-like operating systems, available as freeware via the Internet.

GOLC (Growth Opportunity License Charge)
An IBM software pricing program.

Gold
A specification for Internet-based financial transactions, developed by IBM and the now-defunct Integrion consortium. Gold was later merged with Open Financial Exchange (OFX) to form the Interactive Financial Exchange (IFX) specification. See OFX and IFX.

gopher
A text-based distributed document delivery and retrieval system once used over the Internet. It predates, and has been superseded by, hypertext documents on the Web.

GOSIP (Government Open Systems Interconnection Profile)
A standard issued by the National Institute of Standards and Technology. GOSIP specifies the details of an interoperable Open Systems Interconnection (OSI) configuration for networking products procured by the U.S. government. See OSI.

Government Open Systems Interconnection Profile (see GOSIP)

government-to-business (see G2B)

government-to-constituent (see G2C)

government-to-government (see G2G)

GPO (group purchasing organization)
A healthcare industry term. GPOs provide their members with collective-buying and negotiation services for medical-supply purchases.

GPRS (general packet radio service)
GPRS is a packet-oriented overlay to Global System for Mobile Communications (GSM) networks supporting connection- and connectionless-oriented services and diverse quality-of-service mechanisms. The theoretical maximum speed is 171.2 kilobits per second (Kbps), but real-life user throughput is expected to be 56 Kbps or less. See GSM.

GPRS Roaming Exchange (see GRX)

GPS (Global Positioning System)
A system that uses radio signals from satellites to determine the precise location of any compatible receiver unit. Developed by the U.S. Department of Defense, GPS uses a network of 24 satellites that provide 24-hour positioning information, regardless of the weather. GPS works on the principle of triangulation: By knowing its distance from three or more satellites, the receiver can calculate its position by solving a set of equations. While satellite-based location technology is often referred to generically as "GPS," the U.S.-run GPS network is not the only system that provides such location services. The Russian government runs a satellite-based location system called GLONASS (for "Global Navigational Satellite System"), and plans are in the works for a European global-positioning satellite system called Galileo. See location service.

GPWW (group practice without walls)
An umbrella organization for a group of independent physician practices that performs certain business operations, such as technology procurement.

grade of service
A measure of the quality of service provided by a telephone system. It is calculated based on the probability that a call will encounter a busy signal during the busiest hour of the day.

Graduated Monthly License Charge (see GMLC)

Gramm-Leach-Bliley Act (see FMA99)

granularity
A software, hardware or network system's ability to be modified by altering its components — for example, through changes to the modules in a software package, or to the number of processors in a hardware configuration.

graphical shell
A simple graphical user interface to a character-oriented command language, such as DOS.

graphical user interface (see GUI)

Graphics Device Interface (see GDI)

Graphics Interchange Format (see GIF)

gray scale
A range of gray tones used to create a monochrome image.

ground start
A telephony term describing a signaling method whereby one station detects that a circuit is grounded at the other end.

ground station (see earth station)

Groupe Speciale Mobile (see GSM)

group purchasing organization (see GPO)

groupware
Software that supports interpersonal processes and the objects with which people commonly work. The term was originally coined to describe a class of applications designed to provide electronic support for groups of individuals working together toward a common goal. In that sense, it been applied to applications ranging from unstructured e-mail to rigorously structured workflow systems. Groupware is more useful as a concept when it is broken down into three major stages: communication, coordination and cooperation. In this light, groupware applications can be viewed in terms of the degree and complexity of structure in the group interactions they enable, and the rigor with which those activities are monitored.

GRS (Global Resource Serialization)
An IBM system function designed to manage shared resources in a manner that improve system integrity.

GRX (GPRS Roaming Exchange)
A standard defined by the GSM Association for general packet radio service (GPRS) roaming. The standard enables mobile Internet services to be accessed through an Internet Protocol network managed and operated by a third party. See GPRS.

GSM (Global System for Mobile Communications)
The dominant digital cellular technology for mobile telephone networks in Europe. GSM (formerly called "Groupe Speciale Mobile") utilizes the 905-915 MHz and 950-960 MHz reserved spectrum to provide roaming capability across 18 countries in Europe. GSM 1900, the North American version of GSM, allows the standard to be used in the 1,900 MHz frequency band, which the U.S. Federal Communications Commission and Industry Canada have allocated for personal communication services (PCS). GSM is also the name of the European Telecommunications Standards Institute technical committee responsible for the developing the standard. See PCS.

GSM 1900
The North American version of Global System for Mobile Communications (GSM). GSM 1900 — a modification of the European specification, which operates at 900 megahertz (MHz) — enables GSM to be used in the 1,900-MHz frequency band, which the U.S. Federal Communications Commission and Industry Canada have allocated for personal communications services (PCS). See GSM and PCS.

GSM Association
An industry group representing wireless network operators that use Global System for Mobile Communications (GSM) technology, as well as GSM technology manufacturers and suppliers. Founded in 1987, the association has played a pivotal role in the development of the GSM platform and the global wireless industry. See GSM.

GSR (Gigabit Switch Router)
A family of router products from Cisco Systems.

GSS-API (General Security Services Application Programming Interface)
An information security standard described in Internet Engineering Task Force Request for Comment 1508. GSS-API defines formats for access control, user identification and other information security functions.

GUI (graphical user interface)
A graphics-based interface that uses icons, menus and a mouse clicks to manage user interaction with a system. Originally developed by Xerox, the GUI was popularized by the Apple Macintosh in the 1980s. At the time, Microsoft's operating system, MS-DOS, required the user to type specific commands, but the company added a GUI overlay called "Windows," which eventually became the dominant user interface for personal computers. A comprehensive GUI environment includes four components: a graphics library, a user interface toolkit, a user interface style guide and consistent applications. The graphics library provides a high-level graphics programming interface. The user interface toolkit, built on top of the graphics library, provides application programs with mechanisms for creating and managing the dialogue elements of the windows, icons, menus, pointers and scroll bars in the interface. The user interface style guide specifies how applications should employ the dialogue elements to present a consistent, easy-to-use environment (i.e., "look and feel") to the user. Application conformance with a single user interface style is a key determinant of ease of learning and use, and thus, of application effectiveness and user productivity.