RA is a streaming audio file category format designed to play audio over a wide area network. The RA (RealAudio) file format was developed by RealNetworks in the mid-90s of the last century. The file itself contains encoded audio information, but it may also contain links to audio content. It may contain audio data or reference an audio streaming file. In order to compress the data, they use their own Real compression algorithm with a variable bitrate, as well as a variety of codecs. The .ra file format is a common format required to play streaming audio on the Internet. Real Audio is a standard format for playing audio clips in a web browser. As a rule, they use the RealOne Player to play it. However, due to the fact that it is completely unsuitable and clogged with advertising, they recommend the RealAlternative package. Previously, most radio stations broadcasting online used this particular format. Also until 2009, the format was used on its website by BBC. Currently, the RA format is not so popular among those who broadcast online, since new technologies have already been introduced.
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.