Gateway

A 'tunnel' or 'portal' which computers on one network connect to in order to access other networks. An example would be a corporate network connecting to the Internet, or a home user connecting to an ISP to use the Internet.

Gb

Gigabyte. A size of data, which is 1024 Megabytes. For approximation this is usually rounded-down to 1000 Megabytes.

GIF

One of the most common graphic files used on the Internet, first introduced by Compuserve.

Graphics Card

Also known as Video Card. This is a piece of hardware that produces the images that are displayed on a monitor. If you want to see what you are doing on a PC, then a graphics card is essential - in fact some PCs will not operate without one.

GSM

Global System for Mobile communications. A system used in mobile phones to transfer information in a digital format, whether just voice or actual computer data. Similar to PCN but at a different radio frequency.

GUI

Graphical User Interface. Any type of system that doesn't just use text to show information. For example, Windows is a GUI whereas DOS is not.