What is "blitter"

n. (context computing English) A software or hardware mechanism that blits.

In a computer system, a blitter is a circuit, sometimes as a coprocessor or a logic block on a microprocessor, that is dedicated to the rapid movement and modification of data within that computer's memory. A blitter is capable of copying large quantities of data from one memory area to another relatively quickly, and in parallel with the CPU, while freeing up the CPU's more complex ISA for more general operations.

The name comes from BLIT, which is not an acronym but is often interpreted as BLock Image Transfer. A typical use for a blitter is the movement of a bitmap, such as windows and fonts in a graphical user interface or sprites and backgrounds in a 2D computer game. A blit operation is more than a memory copy, because it can involve data that's not byte aligned (hence the bit in bit blit), and because it may need to handle transparent pixels—pixels which should not overwrite the destination data.