Is a project with unlimited possibilities, the basic idea of which is the creation of an open source media container that works across formats. MKV format involves multiple selectable subtitles, video and audio tracks. Besides, MKV provides an online broadcast, instant rewind of the file and the partition of files into heads.
this format is free, which apparently is one of the reasons for its popularity. The used codecs supports variable bit rates (as a default), and .ogg files usually play back easily on all platforms. All things being equal, the sound quality exceeds that of mp3 somewhat.