Acronym for Graphics Interchange Format.
A FileFormat for palettized images of at most 256 colours. It was designed by CompuServe in the 1980's utilizing the lossless LZW compression Algorithm to make it easier to share images online. This should later become a major headache; see Unisys.
Falling out of favour as PNG becomes more widely supported. Suitable for encoding images with a limited range of tones (logos and icons for exmaple) but poor for encoding digital photography due to the large number of tones generated in digital photography.