| Word |
Description |
| Gamma |
In computer graphics and digital video, this refers to a numerical parameter that describes the nonlinearity of intensity reproduction. Basically, as colors get lighter the human eye has more trouble discerning them, and a gamma setting is used to compensate for this so that shades of color on an object, such as those caused by shadows, can be discerned properly. Incorrect gamma settings can cause colors to look too dark or too light, losing detail to the viewer. |
| Gamma Correction |
The process of altering the gamma of computer graphics, pictures, or video in order to make the picture show up properly and enable the proper recognition of shades of color. Some graphics accelerators have gamma correction features, as early 3D games often had issues with colors appearing too dark. |
| Gateway |
The technical meaning is a hardware or software set-up that translates between two dissimilar protocols, for example America Online has a gateway that translates between its internal, proprietary e-mail format and Internet e-mail format. Another, sloppier meaning of gateway is to describe any mechanism for providing access to another system, e.g. AOL might be called a gateway to the Internet. |
| GB |
1. Giga-Byte. Unit of storage. Abbreviated as GB (not to be confused with Gb, which is giga-bit). For details see gigabyte.
2. Giga-bit. Unit of storage. Abbreviated as Gb, note the small "b" as this distinguishes it from GB.
A Giga-bit is a (230) bits. Since there are 8 bits to a byte, 8 Gb = 1 GB. |
| GDI |
Graphics Device Interface. In Windows the GDI provides a common set of drawing routines (including both text and graphics). The GDI can be used to draw to most devices, such as screens, printers, plotters or bitmap images. Central to the GDI is the concept of a Device Context (DC) which is a handle to the specific device to be written to. |
| Gethostbyaddr |
The gethostbyaddr DNS query is when the address of a machine is known and the name is needed. |
| Gethostbyname |
The gethostbyname DNS quest is when the name of a machine is known and the address is needed. |
| GIF |
(Graphic Interchange Format)
A common format for image files, especially suitable for images containing large areas of the same color. GIF format files of simple images are often smaller than the same file would be if stored in JPEG format, but GIF format does not store photographic images as well as JPEG. |
| GIG |
1. Abbreviation for Gigabyte. GIG implies a single gigabyte, cf GIGS.
2. Abbreviation for Gigahertz. |
| Gigabyte |
Unit of storage, usually abbreviated to GB. 1 gigabyte = 2 to the thirtieth power (230) bytes = 1,073,741,824 bytes = 1024 megabytes. See also terabyte.
Note: Storage devices sold by manufacturers normally assume 1GB = 1,000 MB = 1,000,000,000 bytes. |
| Gigahertz |
A unit of frequency, one gigahertz is one thousand million hertz or one thousand million oscillations (or cycles) per second.
1 gigahertz = 1 GHz = 1,000,000,000 Hz.
|
| GIGS |
1. Abbreviation for gigabytes (plural). Normally used in the context of expressing that space or transfer is large and many gigabytes worth.
2. Abbreviation for gigahertz. Normally used in the context of multiple gigahertz, such as when expressing the clock speed of a cpu. |
| GIS |
Geographic Information System(s). Geographic Information Systems are designed to work with data that is referenced by spatial or geographic coordinates. GIS includes tools and systems for managing, modelling and analysing data that can be referenced by spatial or geographic coordinates. |
| Glitch |
This often refers to a bug in a program that is somewhat different than a freeze or a crash, usually causing erroneous or garbage results to be displayed. The term glitch sounds like a mess, and that’s what programs with glitches create.
|
| GMT |
Greenwich Meridian Time. The time zone from which all other time zones are measured. Now commonly referred to as UTC.
See also UTC, time zone, BST. |
| GNU |
Recursive acronym standing for "GNU's not Unix". An ongoing project by the Free Software Foundation to create a free, freely distributable, set of UNIX like utilities. |
| Google |
Google is the world's most popular search engine. It began as a search project in 1996 by Larry Page and Sergey Brin, who were two Ph.D. students at Stanford University. They developed a search engine algorithm that ranked Web pages not just by content and keywords, but by how many other Web pages linked to each page. This strategy produced more useful results than other search engines, and led to a rapid increase in Google's Web search marketshare. The Google ranking algorithm was later named "PageRank" and was patented in September of 2001. In only a short time, Google became the number one search engine in the world. |
| GP |
1. Group Policy. |
| GPF |
General Protection Fault. This is an error trapped by the OS when an application tries to access memory that it has not been allocated. |
| GPL |
General Public License. Normally taken to the mean the GNU GPL. A license statement from GNU, used on most of their software and on many free software packages from other sources.
|
| Graphics |
omputer graphics are images displayed on a computer screen. They can be either two or three-dimensional. Two-dimensional graphics come in raster or vector formats.
Raster graphics are the most common type of computer graphic and are used for icons, photos, and other basic images. Vector graphics are used for drawings, logos, and other scalable objects. 3D graphics are made up of polygons and can be created with CAD and 3D modeling programs. They are most commonly seen in video games and 3D animations. |
| Grep |
A UNIX program, now also available on other OSes, that allows you to search through one or more text files for a specific text string. As well, Grep allows the replacement of the found string. |
| Grid computing |
Grid computing (or the use of computational grids) is the combination of computer resources from multiple administrative domains applied to a common task, usually to a scientific, technical or business problem that requires a great number of computer processing cycles or the need to process large amounts of data.
One of the main strategies of grid computing is using software to divide and apportion pieces of a program among several computers, sometimes up to many thousands. Grid computing is distributed, large-scale cluster computing, as well as a form of network-distributed parallel processing [1]. The size of grid computing may vary from being small — confined to a network of computer workstations within a corporation, for example — to being large, public collaboration across many companies and networks. "The notion of a confined grid may also be known as an intra-nodes cooperation whilst the notion of a larger, wider grid may thus refer to an inter-nodes cooperation".[2] This inter-/intra-nodes cooperation "across cyber-based collaborative organizations are also known as Virtual Organizations".[3]
It is a form of distributed computing whereby a “super and virtual computer” is composed of a cluster of networked loosely coupled computers acting in concert to perform very large tasks. This technology has been applied to computationally intensive scientific, mathematical, and academic problems through volunteer computing, and it is used in commercial enterprises for such diverse applications as drug discovery, economic forecasting, seismic analysis, and back-office data processing in support of e-commerce and Web services.
What distinguishes grid computing from conventional cluster computing systems is that grids tend to be more loosely coupled, heterogeneous, and geographically dispersed. Also, while a computing grid may be dedicated to a specialized application, it is often constructed with the aid of general-purpose grid software libraries and middleware. |
| GRP |
Gateway Routing Protocol. |
| GSM (Global System for Mobile Communications) |
A 2G digital standard for cellular phone communications that is used in many countries. GSM communications bands range from 900-1800MHz. The GSM initials were initially derived from the French “Groupe de travail Sp�ciale pour les services Mobiles.” |
| Guest OS |
The operating system installed inside a virtual machine (or a partition). In a virtualization solution the guest OS can be completely different from the host OS.
In a partitioning solution the guest OS must be identical to the host OS. |
| GUI |
Stands for "Graphical User Interface," and is pronounced "gooey." It refers to the graphical interface of a computer that allows users to click and drag objects with a mouse instead of entering text at a command line. Two of the most popular operating systems, Windows and the Mac OS, are GUI-based. The graphical user interface was first introduced to the public by Apple with the Macintosh in 1984. However, the idea was actually taken from an earlier user interface developed by Xerox. |
| GUID |
Stands for "Globally Unique Identifier." A GUID is a 128-bit (16 byte) number used by software programs to uniquely identify the location of a data object. Some examples of data that include GUIDs are streaming media files, Windows registry entries, database keys, and various file types. GUIDs are typically written in hexadecimal notation, containing 32 digits, and may look something like this: {12345678-9012-3456-7890-123456789012}.
Globally unique identifiers are also the basis of the GUID Partition Table (GPT). This is a hard disk partitioning scheme proposed by Intel as part of the Extensible Firmware Interface. It is used by Windows PCs as well as Intel-based Macintosh computers. GPT uses GUIDs to define the different partitions on a hard drive. Some examples include the boot partition, the file system partition, and the data partition. Each operating system that supports the GPT partitioning scheme uses specific GUIDs to label each partition. |
| Gustafson’s Law |
In response to Amdahl’s Law on limitation of effectiveness of parallel computing due to a serial (non-parallelizable) component of code, Gustafson’s Law was developed to show that you can achieve over a 1000-fold speed-up using 1024 processors. It states that if the size of most problems is increased sufficiently, you can achieve any given efficiency by increasing the amount of processors. |
| GZIP |
GNU ZIP
A VRML file compression format similar to ZIP compression. In VRML 2.0, the scene graph file can be "GZIP'd," and the file will automatically decompress for rendering on the client machine. Compressed files reduce download time.
See also: scene graph, VRML, ZIP |
