A pixel (or picture element) is a single point in a raster image. The pixel is the smallest addressable screen element, it is the smallest unit of picture which can be controlled. Each Pixel has its address. The address of a pixel corresponds to its coordinate. Pixels are normally arranged in a 2-dimensional grid, and are often represented using dots or squares. Each pixel is a sample of an original image, where more samples typically provide more-accurate representations of the original.