Raster graphics are composed of pixels that together form images. Pixels are the smallest unit that make up raster images, including digital photos. Raster images were initially used in early computer and video games due to the low screen resolutions at the time. While raster images can look natural like drawings, they become pixelated if enlarged too much since individual pixels become visible. Common file types for raster images are JPG, PNG, and GIF. Raster graphics are essential for graphic designers to understand as they are widely used online and in web design.