GIF vs. JPG
by Susan Delap

Here is a graphic saved as both a GIF and a JPG of about the same file size so you can see for yourself the difference. (Thanks to Rick Aster for supplying the graphic.)

First the GIF.

Now the JPG.

Notice that the JPG's bands of solid color are mottled, and the text has shadowy colors around it. The GIF is clearer and sharper. So use GIFs for graphics like this. Use JPGs for photographs that have lots of colors where the color mottling won't be noticeable.