An area of memory used to hold a frame of data. Typically used for screen output, the buffer is the size of the maximum image that can be displayed on the screen. The memory, which is either a separate memory bank on the display adapter or a reserved part of regular memory, holds a bitmapped image while it is being "painted" on screen. Sophisticated graphics systems are built with several memory planes, each holding one or more bits of the pixel. See also frame grabber.