The GIF format is one of the most popular image formats used on the Internet. GIF images are normally used for logos, shapes and icons. The format is based on the lossless LZW compression algorithm and is superb for compressing large image areas of the same color. Another important feature of GIF is that it supports animation.
However, since GIF creates a color table with a maximum of 256 colors, it is not suitable for graphics which have long stretches of continuous-tone in them (for example, photographs). The number of colors can be reduced in order to reduce the file size. Anti-aliasing should not be used within GIF images as the GIF format does not implement these features efficiently.