You've seen them on the interwebs: little boxes in the margins of your beloved blog pages, moving and flashing, just begging for your attention. But what is a GIF, really?
A .gif file is a form of computer image that moves as an animation, because it consists of frames, like a movie with no sound. Just a few frames can help tell a story, express an emotion, or demonstrate some instructions. Usually people make these because the file size is small.