G
gain
  The ability to change the audibility of the sound, such as during a fade in or fade out of music.
GDI object
  See graphics device interface object.
generic class
  See class template.
global
  Pertaining to information available to more than one program or subroutine. IBM.
global scope
  See file scope.
global variable
  A symbol defined in one program module that is used in other independently compiled program modules.
glyph
  A graphic symbol whose appearance conveys information; for example, the vertical and horizontal arrows on cursor keys that indicate the directions in which they control cursor movement.
GMT
  See Greenwich Mean Time.
graphical user interface (GUI)
  A type of computer interface consisting of a visual metaphor of a real-world scene, often of a desktop. Within that scene are icons, representing real-world objects, that the user can access and manipulate with a pointing device. See command line interface.
graphic attributes
  Attributes that apply to graphic primitives. Examples are color, line type, and shading-pattern definition.
graphic primitive
  In computer graphics, a basic element, such as an arc or a line, that is not made up of smaller parts and that is used to create diagrams and pictures. IBM.
graphics
  A picture defined in terms of graphic primitives and graphic attributes.
graphics device interface (GDI) object
  An object such as a brush, pen, or bitmap. All graphics device interface (GDI) objects are owned by the process that also owns the thread. See user object, kernel object.
Greenwich Mean Time
  The basis of standard time. Now commonly replaced by Coordinated Universal Time (UTC).
GUI
  See graphical user interface.