Graphical User Interface: interface between operating system and user that uses mouse and keyboard for inputs and a graphics screen for outputs. It represents basic objects and tasks by graphical symbols and operations, which can be arranged freely on the screen (the ``desktop'').
|starting a program||double clicking with a mouse button|
|working with files||dragging icons, symbolizing the files|
|choosing actions||clicking on menues|
Window: usually rectangular area on the screen, which represents input and output of an application. Windows allow to work with several applications at once or they structure many possible views of one complex application.
|border||change size of the window|
|title bar||move the window|
|buttons||minimize/maximize the window or close the application|