GUI

A graphical user interface (GUI) is a type of user interface that allows people to interact with electronic devices through graphical elements such as windows, icons, buttons, and menus, rather than text-based commands. GUIs are designed to be intuitive and enable point-and-click or touch-based interaction.

The concept emerged from research at Xerox PARC in the 1970s with the Alto and Star projects, popularized by Apple's Macintosh in 1984 and later Microsoft Windows. Early GUIs used desktop metaphors; over time, innovations included direct manipulation, drag-and-drop, and visual feedback.

GUIs are typically event-driven, responding to user actions via input devices like mouse, keyboard, touch, or stylus. Common elements include windows, panels, dialogs, menus, toolbars, icons, and widgets such as buttons, sliders, and text fields. Layout and hierarchy help organize information and controls.

GUIs are used in desktop and laptop operating systems, mobile devices, embedded systems, and web applications that implement graphical interfaces. Web GUIs are built with HTML, CSS, and JavaScript and run in browsers, while native GUIs are provided by GUI toolkits like Qt, GTK, Cocoa, or Win32.

Good GUI design emphasizes clarity, consistency, discoverability, and accessibility, supporting users with disabilities.