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.
Is a binary stream media container format that combines several codecs of texts, subtitles, audio and video data. It can be used on web pages for video playback. It has a lot to do with the OGG format. Exists support for popular codecs MPEG-4 and MP3.