Is a multimedia container for playing audio and video in karaoke mode. There are several options for playback, which switch off all of the streams. This format is supported by a few PC players, but is widely used for DVD-players and home theater systems.
Is a video format similar to MP4. The difference between the formats is their developers and protection. Apple company, has developed a format that has provided DRM-lock for M4V. Video files in this format are downloaded from iTunes.