In computing, a graphical user interface (GUI,[1] sometimes pronounced "gooey" (or "gee-you-eye"))[2] is a type of interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLIs),[3][4][4] which require commands to be typed on the keyboard.
A 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 (NLS). The concept of hyperlinks was further refined and extended to graphics by researchers at Xerox PARC and specifically Alan Kay, who went beyond text-based hyperlinks and used a GUI as the primary interface for the Xerox Alto computer, released in 1973. Most modern general-purpose GUIs are derived from this system.