M2TS (acronym for MPEG-2 Transport Stream) is a file format used for video tracks on Blu-ray discs. The M2TS format is mainly suitable to multiplex audio, video and other streams.
M2TS typically appears on Blu-ray Discs because M2TS is the de-facto high-definition BDAV format.
Because it is related to the newly-developed Blu-ray discs, the M2TS format is supported only by a limited number of multimedia players because of its rather new technology.
M2TS-compatible apps may also allow their users to export their files to more popular formats.