Why use sprite animation?
Using an animated GIF might be easier and wouldn’t require as much coding, but sprite animation offers two distinct advantages: First, with sprite animation we have the option of using PNG images with alpha transparency (GIF offers only binary transparency and MNG support by the major browsers just never took off). Second, we can control the frame rate of sprite animations programatically, so a single image file can be animated at any speed by simply typing in the desired frame rate—no need to create a whole new version of the image file.
