<operating system> (GUI) The use of pictures rather than just words to represent the input and output of a program. A program with a GUI runs under some windowing system (e.g. The X Window System, MacOS, Microsoft Windows, Acorn RISC OS, NEXTSTEP). The program displays certain icons, buttons, dialogue boxes, etc. in its windows on the screen and the user controls it mainly by moving a pointer on the screen (typically controlled by a mouse) and selecting certain objects by pressing buttons on the mouse while the pointer is pointing at them. This contrasts with a command line interface where communication is by exchange of strings of text. Windowing systems started with the first real-time graphic display systems for computers, namely the SAGE Project [Dates?] and Ivan Sutherland's Sketchpad (1963). {Douglas Engelbart}'s Augmentation of Human Intellect project at SRI in the 1960s developed the On-Line System, which incorporated a mouse-driven cursor and multiple windows. Several people from Engelbart's project went to Xerox PARC in the early 1970s, most importantly his senior engineer, {Bill English}. The Xerox PARC team established the WIMP concept, which appeared commercially in the Xerox 8010 (Star) system in 1981. Beginning in 1980(?), led by Jef Raskin, the Macintosh team at Apple Computer (which included former members of the Xerox PARC group) continued to develop such ideas in the first commercially successful product to use a GUI, the Apple Macintosh, released in January 1984. In 2001 Apple introduced Mac OS X. Microsoft modeled the first version of Windows, released in 1985, on Mac OS. Windows was a GUI for MS-DOS that had been shipped with IBM PC and compatible computers since 1981. Apple sued Microsoft over infringement of the look-and-feel of the MacOS. The court case ran for many years. [Wikipedia]. (2002-03-25)

The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, instead of text-based UIs, typed command labels or text navigation.

A graphical user interface builder (or GUI builder), also known as GUI designer or sometimes RAD IDE, is a software development tool that simplifies the creation of GUIs by allowing the designer to arrange graphical control elements (often called widgets) using a drag-and-drop WYSIWYG editor. Without a GUI builder, a GUI must be built by manually specifying each widget's parameters in source-code, with no visual feedback until the program is run.

A vector-based graphical user interface is a mostly conceptual type of graphical user interface where elements are drawn using vector rather than raster information.

Textual User Interface

<jargon> Working under a non-window-based operating system (e.g. MS-DOS) as opposed to a graphical user interface (e.g. Microsoft Windows). An MS-DOS text-based program uses a screen with a fixed array of 80x25 or 80x40 characters. Examples are WordPerfect before version 5.1 and Microsoft Word. (1995-03-16)

<interface> (TUI) Either a text-based version of a GUI, or a full-screen version of a CLI. (2003-10-21)

In computing, text-based user interfaces (TUI) (alternately terminal user interfaces, to reflect a dependence upon the properties of computer terminals and not just text), is a retronym describing a type of user interface (UI) common as an early form of human–computer interaction, before the advent of graphical user interfaces (GUIs). Like GUIs, they may use the entire screen area and accept mouse and other inputs.

User interface (UI) design or user interface engineering is the design of user interfaces for machines and software, such as computers, home appliances, mobile devices, and other electronic devices, with the focus on maximizing usability and the user experience. In computer or software design, user interface (UI) design primarily focuses on information architecture.