Bitmap
From The Glossary of Digital Photography
A raster graphic in which each bit is mapped to a rectangular grid of pixels. In digital photography, each pixel is represented by 3 bytes, one each for red, green, and blue (RGB). A bitmap is represented by the total number of pixels and the bit depth, or number of bits per pixel. The total number of pixels is calculated by multiplying the number of pixels in the height by the number of pixels in the width of the bitmap. The number of bits per pixel determines the number of possible color combinations.
