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.
CAF is a highly specialized audio file format. It was developed by Apple Computer, its name is an abbreviation for Core Audio File. It is a container format for audio files. CAF is distinguished by its large size from many other similar audio file formats. At the same time, the compression ratio is, on the contrary, much less than that of files of a different format, which allows compression without loss of quality compared to the original. The disadvantages of the CAF format are that not all popular players support it, and therefore such files need to be converted.