JPEG and MPEG are the abbreviated names of two standards groups that fall under both the International Organization for Standardization and the International Electrotechnical Commission. JPEG is the Joint Photographic Expert Group, which works on the standards for compression of still digital images. MPEG is the Moving Picture Expert Group, which works on the standards for compression of digital movies. JPEG and MPEG are also the names for the standards published by the respective groups.

Digital images or video are compressed primarily for two reasons: to save storage space for archival, and to save bandwidth in communication, which saves time required to send the data. A compressed digital image or video can be drastically smaller than its original size and saves a great deal of storage space. Upon retrieval, the data can be decompressed to get back the original image or video. When one needs to...