an apple class that defines objects that manage and coordinate the windows an application displays on the screen
The NSWindow class defines objects (known as windows) that manage and coordinate the windows an application displays on the screen. A single NSWindow object corresponds to at most one onscreen window. The two principal functions of a window are to provide an area in which views can be placed and to accept and distribute, to the appropriate views, events the user instigates through actions with the mouse and keyboard.
