Bit blit
Bit blit (also written BITBLT, BIT BLT, BitBLT, Bit BLT, Bit Blt etc., which stands for bit block transfer) is a data operation commonly used in computer graphics in which several bitmaps are combined into one using a boolean function. The operation involves at least two bitmaps: a "source" (or "foreground") and a "destination" (or "background"), and possibly a third that is often called the "mask".