We've already talked about the use of bitmaps in icons and cursors. Windows also includes a resource type called BITMAP.
Bitmaps are used for two major purposes. The first is to draw pictures on the display. For instance, the Windows display driver files contain lots of tiny bitmaps used for drawing the arrows in scroll bars, the check mark in pull-down menus, the system menu box, the size box, check boxes, and radio buttons. Programs such as PAINTBRUSH use bitmaps to display a graphics menu.
The second major use of bitmaps is to create brushes. Brushes, you'll recall, are patterns of pixels that Windows uses to fill an area of the display. (Chapter 9 discusses a third and less common use of bitmaps, as selection items in menus.)