The two standard graphic formats used on web sites is GIF and JPG. Both have features that make them best suited for a particular job. A general rule of thumb you can follow is: - use GIFs for illustrations, clip art, and images with large areas of flat color - use JPGs for photographs and images with gradient colors (colors that blend together) There are also two unique features that GIFs have which make them useful in certain situations: - the GIF file format can contain multiple images and display those images in a sequence. This allows a single graphic image to have motion or appear animated. (You've seen this likely before in banner ads on web sites.) - GIF images can have a transparent background. This is especially useful if you have an image which might be displayed on top of a page color that changes. If your GIF image has a transparent background, the color of the page will show through, providing a professional appearance. More information at the link below: http://www.webopedia.com/DidYouKnow/Internet/2002/JPG_GIF_PNG.asp