Workbench utilizes the Amiga's native windowing system called Intuition to provide the graphical user interface. Intuition manages the rendering of screens, windows, and gadgets (graphical elements, equivalent to widgets). Later versions of AmigaOS enhanced the interface with more complex object-oriented widget systems, such as gadtools.library and BOOPSI (AmigaOS 2.0 and later) and ReAction (AmigaOS 3.5 and later). Intuition also handles user input events, such as, input from the keyboard and mouse. Workbench requires a two button mouse, where right click operates pull-down menus and left click is used for all other purposes.