A GUI includes icons, cursors and buttons, these graphically represented elements are sometimes provided with effects and sounds, transparency, drop shadows ... . Using these objects, a user can use the computer without having to use or know commands from the console.
The best known of the Graphical User Interface is the Windows Desktop, which is called Start on Android!
To make a graphical user interface as user-friendly as possible, there are various elements and objects that the user uses to interact with the operating system itself or with the software, programs, applications, ... to interact.
Also the 3D games can be seen as a kind of 3D graphical user interface, much more is not here, because the actual events take place here only in bits and bytes. We are only fooled on the screen that something is happening!
3.) How does a GUI work?
A graphical user interface uses windows, icons, menus, selection boxes, list items to execute commands or display data. A GUI is controlled with a mouse, keyboard!
For example, when you start / open a program, the mouse pointer is moved to the icon of the program and started by a double click.