A general term for a coded bitstream such as audio or video. Elementary streams are made up of packs of packets.

There are two types of elementary streams: video (the output from an MPEG video encoder) and audio (the output of an audio encoder). These streams are converted into Video PES and Audio PES before they are combined into a single stream.

Defined by MPEG communication protocol. An elementary stream contains only one kind of data, e.g. audio, video or closed caption. An elementary stream is often referred to as "elementary", "data", "audio", or "video" bitstreams or streams.