The GIF (pronounced DJIF by many, such as its designer; perceptible GIF with a hard G by many others) stands for Graphics Interchange Format and is one of the two most frequent file formats for graphic images on the World Wide Web. Another is the JPEG.
On the net and elsewhere on the Internet (by way of example, bulletin board services), the GIF has become a de facto standard form of image. The LZW compression algorithm used in the GIF format is owned by Unisys, and businesses that make products that exploit the algorithm (like the GIF format) have to license its use from Unisys. Although their licensing announcement indicates that it’s a requirement, in practice, Unisys has not required users of GIF images to obtain a license. Unisys claims that acquiring a license from them does not involve a fee.
The GIF uses the 2D raster data type and is encoded in binary. There are two variations of the format, 87a and GIF89a. Version 89a (July, 1989) allows for the possibility of an animated GIF, which can be a brief series of images within a single GIF file. A GIF89a may also be given for interlaced GIF presentation.
Meanwhile, many GIF downloaders and Web site builders on the Web are still ignorant of or indifferent to the requirement to get a license from Unisys for their algorithm’s use.