Transport stream (TS, TP, MPEG-TS, or M2T) is a communications protocol for auio, video, and data which is specified in MPEG-2 Part 1, Systems (ISO/IEC standard 13818-1). Its design goal is to allow multiplexing of digital video and audio and to synchronize the output. Transport stream offers features for error correction for transportation over unreliable media, and is used in broadcast applications such as DVB and ATSC. It is contrasted with program stream, designed for more reliable media such as DVDs.