AC3 is a sound file format. Its name is the abbreviation for Audio Codec 3. The format was developed by Dolby Laboratories, Inc as a modern and efficient sound compression technology. AC3 files feature Dolby Digital multi-channel surround sound. In this regard, they are widely distributed as a format for DVDs, movie theaters and game consoles. However, you can evaluate all the advantages of such files only if you have the appropriate acoustics for surround sound. An audio file of the specified format can include up to six sound channels, which creates a presence effect for the listener.
MKV is an open container format for audio and video data created by Russian developers. The name of the format originates from the name of the project - Matroska (Matryoshka) with the addition of the first letter of the word Video. This format is considered an alternative to the much more popular AVI, but has not yet reached such a scale of distribution. MKV files are quite common among owners of fairly old mobile devices with Symbian OS and at the same time among those who prefer to watch video in FullHD, since MKV has good dynamics of transmitting video / audio streams. MKV with a wide range of features, in particular, storing audio tracks in different languages, is easy to edit, there are no freezes in large files.