MKV, Matroska Video File (.mkv)
The MKV Video file format
The MKV (Matroska Multimedia Container) is a free and open standard for the storage of video data. There is no limit to the number of audio, video, images, and subtitle tracks the file can contain, meaning it is a convenient way to store movies, entire TV series, and more. The raw format allows the user to jump to all of the individual data tracks. The royalty free Matroska project's technical specifications are available for the use by anyone. The Matroska libraries are licensed under the LGPL (LGNU Lesser General Public License) with parsing and playback licensed through the BSD licenses.
Technical details of MKV files
File saved as MVK are supposed to save every track, whether it is audio, video, picture or subtitle, into a different dataline. Thus, it's similar to various other container formats like MP4 or AVI, although usually, when packaging an MKV file, users rarely bundle all the tracks within the file. The majority of media players do not natively support MKV files, and the user needs to make use of a special software that plays such media files in order to access its content normally, for example the VLC player.