GIF - stands for "Graphics Interchange Format" and is one of the two most common file formats for graphic images on the World Wide Web. The other is the JPEG.
The GIF uses the 2D raster data type and is encoded in binary. There are two versions of the format, 87a and GIF89a. Version 89a (July, 1989) allows for the possibility of animation, which is a short sequence of images within a single GIF file. The animation can be optimized to include only the areas that are changing from frame to frame. A GIF89a can also be specified for interlaced GIF presentation.
The GIF format is owned by Unisys, and companies that make products that exploit the algorithm (including the GIF format) need to license its use. In practice, Unisys has not required users of GIF images to obtain a license, although their licensing statement indicates that it is a requirement. Unisys says that getting a license from them does not necessarily involve a fee.
A patent-free replacement for the GIF, the Portable Network Graphics (PNG) format, has been developed by an Internet committee and major browsers support it or soon will.