As versatile as the World Wide Web is, it sure doesn’t support very many graphics formats—only three, in fact. (Aside from Scalable Vector Graphics, or SVG, supported by HTML5, but that’s another story.) Internet browsers support only three bitmap image formats: GIF, JPEG, and PNG. The type you should use depends primarily on the type of image (its content), you are saving.
The following description of each file format contains information sometimes critical to achieving the best possible quality, information such as the file’s properties, and its best uses. But first, here’s a word about compression.