Learn in the textbookHow Video Works and Its File Formats
DefinitionMPEG is the umbrella name for a family of standards centered on methods for compressing video and audio data.
ExplanationNeighboring frames tend to look very much alike, so MPEG video compression stores only the differences from nearby frames for everything except reference frames, which cuts the data size sharply. The family has numbered standards for different uses, such as MPEG-2 for DVDs and digital broadcasting, and some, like MPEG-4, even define the file format that holds the compressed data. The family also includes audio-only standards; MP3, for example, comes from the audio part of MPEG-1.
AnalogyIt is like describing a series of photos with the same background: instead of redrawing everything each time, you just say "the person moved a little to the right since the last one."
Memory hookMPEG comes from the Moving Picture Experts Group, the body of experts that wrote the standards. A "moving picture" is simply video.