A Graphical User Interface (or GUI) is a methodology that allows users to interact with a computer system using graphical elements such as icons, buttons, windows, and menus. The GUI provides a visual representation of the features and functionality, making it easier for users to interact with and control the software or device through visual elements. In other words, the user clicks on icons to start apps, and selects commands from menus to execute operations or tasks.
GUIs are widely used in modern computing, ranging from desktop operating systems and mobile devices to embedded systems, and point-of-sale terminals. Microsoft Windows, MacOS, iOS, Linux, and Android all use a Graphic User Interfaces.