GIF

GIF is a bitmap image format that stores indexed-color images and supports transparency and frame-based animation. Its lossless compression works best on images with broad areas of uniform color.

Indexed color: A color representation in which each pixel points to an entry in a limited palette. GIF pixels use palette indices rather than storing full color values directly.
CompuServe: A U.S. online service founded in 1969 that provided consumer information and communication services. CompuServe introduced GIF in 1987 for sharing color images across its network.
Animated GIF: A GIF file containing multiple timed image frames that play as an animation. This is the format’s best-known use for short, looping motion.
PNG: A lossless raster image format supporting indexed and full-color images with alpha transparency. PNG improves still-image color depth and transparency without GIF’s single transparent palette entry.
Lempel–Ziv–Welch compression: A lossless compression algorithm that replaces repeated symbol sequences with codes in a growing dictionary. GIF uses this algorithm to compress image data without losing pixel values.
Steve Wilhite: An American computer scientist who led the development of the GIF format at CompuServe. Wilhite’s team created the original GIF specification.
GIF89a looping extension: A GIF extension introduced by Netscape that specifies repeated playback of an animation. It enabled the endlessly looping behavior common in animated GIFs.
JPEG: A family of image compression standards designed mainly for photographic images. JPEG handles continuous-tone photographs far more efficiently than GIF.
GIF color table: A GIF data structure mapping palette indices to RGB color values. Each GIF image can draw colors from a global or local color table.
GIF87a: The 1987 version of the Graphics Interchange Format specification. This first GIF specification established the format’s core image and compression structures.

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