The GIF (Graphics Interchange Format) is a 8-bit compressed (LZW, lossless) bitmap image format. GIF also supports animations by sequencing a number of individual images. The format supports 256 colors which makes the format unsuitable for photographic images. The color limitations and the fact that the LZW compression is proprietary spawned development of the PNG (png) format.
Example of an animated GIF image. Image from Wikipedia Commons