Abbreviated to GUI. The official definition is rather dry: the interface between an operating system or a program and the person using it. This actually means a way of representing files, functions and folders with little images called icons. Windows is a GUI that makes it easier to operate a PC. Before Windows existed you had to type in lines of commands to control the computer. With a GUI such as Windows you can point and click on an icon using the mouse rather than typing in the filename.
