Graphics Interchange Format, GIF (CompuServe GIF) is a graphics format widely used on the World Wide Web, both for images and for animations. The format was developed by CompuServe in 1987 to provide a color image format for their file downloading areas, replacing their earlier RLE format in black and white. GIF became popular because they could use the LZW compression algorithm (Lempel Ziv Welch) for compressing the image, which was more efficient than the algorithm Run-length encoding (RLE) used by the PCX and MacPaint formats. Therefore, large images could be downloaded in a reasonable period of time, even with very slow modems.
Truevision TGA, often referred to as TARGA, is a raster graphics file format created by Truevision Inc. (now part of Avid Technology). It was the native format of TARGA and VISTA boards, which were the first graphic cards for IBM-compatible PCs to support Highcolor/truecolor display. This family of graphic cards was intended for professional computer image synthesis and video editing with PCs; for this reason, usual resolutions of TGA image files match those of the NTSC and PAL video formats. TARGA is an acronym for Truevision Advanced Raster Graphics Adapter;TGA is an initialism for Truevision Graphics Adapter.