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.
AAC is a sound encoded file format developed by Fraunhofer IIS, AT&T, Dolby and Sony. Its name stands for Advanced Audio Coding. The AAC format is an industry standard and was created as an improved alternative to the most common MP3 audio file format. AAC files do have slightly improved features compared to MP3s. Let's say this format provides the opportunity for improved processing of frequencies above 16 kHz. At the same time, the sound quality of AAC files is closer to the original sound source.