A computer output device where each pixel displayed on the monitor screen corresponds directly to one or more bits in the computer's video memory. Such a display can be updated extremely rapidly since changing a pixel involves only a single processor write to memory compared with a terminal or VDU connected via a serial line where the speed of the serial line limits the speed at which the display can be changed.

Most modern personal computers and workstations have bitmap displays, allowing the efficient use of graphical user interfaces, interactive graphics and a choice of on-screen fonts. Some more expensive systems still delegate graphics operations to dedicated hardware such as graphics accelerators.

The bitmap display might be traced back to the earliest days of computing when the Manchester University Mark I(?) computer, developed by F.C. Williams and T. Kilburn shortly after the Second World War. This used a storage tube as its working memory. Phosphor dots were used to store single bits of data which could be read by the user and interpreted as binary numbers.