A graphical user interface (GUI) (IPAEng: ˈguːiː) is a type of user interface which allows people to interact with electronic devices like computers, hand-held devices (MP3 Players, Portable Media Players, Gaming devices), household appliances and office equipment. A GUI offers graphical icons, and visual indicators as opposed to text-based interfaces, typed command labels or text navigation to fully represent the information and actions available to a user. The actions are usually performed through direct manipulation of the graphical elements. 1

The term GUI is historically restricted to the scope of two-dimensional display screens with display resolutions capable of describing generic information, in the tradition of the computer science research at Palo Alto Research Center (PARC) (formerly Xerox PARC and still a subsidiary of Xerox).The term GUI earlier might have been applicable to other high-resolution types of interfaces that are non-generic, such as videogames, or not restricted to flat screens, like volumetric displays. 2

History

main: History of the graphical user interface

Precursors

The precursor to GUIs was invented by researchers at the Stanford Research Institute, led by Douglas Engelbart. They developed the use of text-based hyperlinks manipulated with a mouse for the On-Line System. The concept of hyperlinks was further refined and extended to graphics by researchers at Xerox PARC, who went beyond text-based hyperlinks and used a GUI as the primary interface for the Xerox Alto computer. Most modern general-purpose GUIs are derived from this system. As a result, some people call this class of interface a PARC User Interface (PUI) (note that PUI is also an acronym for perceptual user interface).

Ivan Sutherland developed a pointer-based system called Sketchpad in 1963. It used a light-pen to guide the creation and manipulation of objects in engineering drawings.

PARC User Interface

The PARC User Interface consists of graphical widgets (often provided by widget toolkit libraries) such as windows, menus, radio buttons, check boxes and icons. The PARC User Interface employs a pointing device in addition to a keyboard. These aspects can be emphasized by using the alternative acronym WIMP, which stands for Windows, Icons, Menus and Pointing device.

Evolution

Following PARC the first GUI-centric computer operating model was the Xerox 8010 Star Information System in 1981.

The GUIs familiar to most people today are Microsoft Windows, Mac OS X, and the X Window System interfaces. Apple, IBM and Microsoft used many of Xerox's ideas to develop IBMs Common User Access specifications that formed the basis of the user interface found in Microsoft Windows, IBM OS/2 Presentation Manager, and the Unix Motif toolkit and window manager. These ideas evolved to create the interface found in current versions of the Windows operating system, as well as in Mac OS X and various desktop environments for Unix-like systems. Thus most current GUIs have largely common idioms.