Pixel, in computer science, short for picture element; sometimes called a pel. One spot in a rectilinear grid of thousands of such spots that are individually “painted” to form an image produced on the screen by a computer or on paper by a printer. Just as a bit is the smallest unit of information a computer can process, a pixel is the smallest element that display or print hardware and software can manipulate in creating letters, numbers, or graphics.

An image can also be represented in more than two colors—for example, in a range of grays.

If a pixel has only two color values (typically black and white), it can be encoded by 1 bit of information. If more than 2 bits are used to represent a pixel, a larger range of colors or shades of gray can be represented: 2 bits for four colors or shades of gray, 4 bits for sixteen colors, and so on. Typically, an image of two colors is called a bit map, and an image of more than two colors is called a pixel map.