A Graphics Interchange Format, or GIF, file is a file format for images. It is a bitmap file with a color range of 1 to 8 bits and a maximum image size of 64,000 by 64,000 pixels.
The GIF format was introduced by Compuserve in 1987 for use with its online service. Each image uses a 24-bit color palette that can support 256 colors per image in its palette table. It has become one of the most common file formats for images and is supported by a very wide range of software.
Despite the relatively old age of the file format, it continues to remain popular as it supports animation with lossless data compression. As of 2014, animated GIFs are still commonly seen on websites and message boards.
The LZW compression technique used for GIF files was the subject of a patent dispute for a number of years. Beginning in 1995, the patent holder Unisys attempted to charge licensing fees for use of the file format. The patents expired worldwide in 2004, and the GIF format can now be used freely.
The pronunciation of GIF has also been the subject of long debate. The original creators of the format pronounced it with a soft "g", similar to the peanut butter brand, Jif.