game port - fifteen pin, female port (usually) on an expansion card for plugging in a joystick.

general protection fault [GPF] - An addressing error, caught by the processor's memory protection hardware, that cannot be attributed to any expected condition such as a page fault.

GIF [Graphic Interchange Format] - Format used for displaying bitmap images on World Wide Web pages, usually called a "gif" because .gif is the filename extension. These files use lossless compression and can have 256 colors. JPEG and GIF are commonly used for images on the Web; JPEG is considered best for photos and GIF for other graphic images.

gigabyte {gig-a-bite} [GB] - One billion bytes (1,073,741,824).

greyscale - A black-and-white image. Literally, it is the range of neutral shades of grey spanning from white to black. The term is typically used when editing photos on software (where you can convert a colour digital image to a black-and-white photo) and in printing (where you can choose to print colour pages as greyscale only to conserve color inks).

GUI {goo-ee} [Graphical User Interface] - The use of pictures rather than just words to represent the input and output of a program. A program with a GUI runs under some windowing system (e.g. Microsoft Windows). The program displays certain icons, buttons, dialogue boxes, etc. in its windows on the screen and the user controls it mainly by moving a pointer on the screen (typically controlled by a mouse) and selecting certain objects by pressing buttons on the mouse while the pointer is pointing at them. Though Apple Computer would like to claim they invented the GUI with their Macintosh operating system, the concept originated in the early 1970s at Xerox's PARC lab.