The menu bar's purpose is to supply a common housing for window- or application-specific menus which provide access to such functions as opening files, interacting with an application, or displaying help documentation or manuals. Menu bars are typically present in graphical user interfaces that display documents and representations of files in windows and windowing systems but menus can be used as well in command line interface programs like text editors or file managers where drop-down menu is activated with a shortcut or combination key.