The Graphics Interchange Format (or GIF for short) has long been one of the most popular image formats among computer users and programmers. It is a highly portable format because of its lightweight coding and was the first image able to be processed over the Internet in the early 1990s. Since then, the GIF has remained popular, but due to some coding issues, is being phased out in lieu of a successive format.
In 1987, CompuServe unveiled the first GIF file, created so that images could be transmitted through special download portals used by the CompuServe network. The previous format, Run-Length Encoding (RLE), could not handle images in color. GIF was the first format that allowed colored images to be transmitted. Fittingly, the GIF was also the first format that could be transmitted over the Internet. The JPEG file format, which is the GIF's closest competitor, was introduced later, with the advent of the Mosaic browser.
The main types of GIF images are 87a and 89a. 87a is a simpler type of image and has support for only one stationary picture. 89a however, supports multiple images, which can be compressed into a single GIF file. These images then can be strung together to create a crude "slideshow" animation, called an animated GIF or anigif.
The quality of GIF images has greatly improved as the format has evolved. While the initial GIF files only had support for 256 colors, advanced blending and transparency techniques have made it so that more colors can be created. For their petite filesize, GIF files have very good quality, and modern innovations have made their quality almost on par with competitors.
Although GIFs are still widely used, especially on the Web, the format is slowly being phased out due to a purported patent infringement in the GIF coding. Its successor, the PNG format, uses a simular compression technique to the GIF format, which keeps filesizes low but also handles True Color encoding, which provides more color accuracy than regular GIFs.
Several other image formats compete with the GIF. The most popular is the JPEG, which was the second image type introduced on the Web. The JPEG uses more complex coding, which allows for better image quality, especially for complex colors with soft palettes. Another alternative is the TIFF format, which features advanced pixel encoding and is capable of displaying complex, scientific-quality images.