Graphical user interface

The graphical user interface (often referred to as a GUI), now the almost universal form of user interface to computing devices, is based on images, now displayed on a bit-mapped display, but at first with vector graphics on a CRT.

The user interacts with the operating system and applications with a pointing input device, which is a key input form (although the keyboard is still used). The first pointing device was the light pen, then the mouse, and now the touch-pad. Recently, the pointing device has been used to supplant the keyboard in some system, with hand-writing recognition.

History

The first GUI was associated with the SAGE air defense system. The next steps were taken by Douglas Engelbart of the Augmentation Research Center at the Stanford Research Institute. That work was taken up at the nearby Xerox PARC, with the ground-breaking Xerox Alto project, the first personal computer.