G

gamma

The relationship between the intensity of color and its luminance. Also the type of radiation wave that converted Dr. Banner into the Hulk.

gamma correction

A method of compensating for the loss of detail that the human eye perceives in dark areas.

glyph

A distinct visual representation of one character (such as a lowercase z), multiple characters treated as one (such as the ligature ), or a nonprinting character (such as a space).

grid fitting

The process of modifying characters at small point sizes so that they fit the grid of dots on the relatively coarse display screen. The font designer provides a set of instructions (also known as hints) for a TrueType or PostScript font that tells Mac OS X how to modify character outlines to fit the grid.

group

Used to simplify the assignment of system privileges for clusters of users that have identical levels of access.

guest

A network user who is not identified by a name and password.

GUI (Graphical User Interface)

A means of interacting with and controlling a computer by manipulating graphical objects shown on the display, such as windows, menus, and icons. The opposite of CLI.