RM is a video file format developed by RealNetworks. It uses the RealPlayer player, that is, a program for streaming audio and video files. The format contains audio and video data or links to streaming, which can be played back as it downloads. The RealMedia Player program was in great demand when they connected to the Internet using a modem, and when there was practically no broadband access to the global network. The large compression ratio of the format provided the opportunity to carry out online transmission of video and audio data. The quality of the output file, as a rule, was low. Today, such files are often used in order to broadcast Internet radio and Internet video. In the .RM format, music and video are found on the global network or on Western cable channels, on Internet radio stations. Support for this format is carried out by such mobile phones and smartphones as Nokia, Ericsson, Sony, iPhone, as well as mobile devices that operate on the Google Android operating system. Files with the extension .RM are compressed using proprietary codecs RealVideo and RealAudio. Individual Real Media files can be played using a VLC media player that partially supports RM files.
WMA is a widespread licensed audio stream compression format. Created in 1999 by Signal Processing Group, a member of the IT giant Microsoft. Initially, this company created WMA as a competitor to the popular MP3 format. The name WMA is an abbreviation for Windows Media Audio. Among the advantages of this format is the support of almost all Windows systems and devices, as well as the similarity in characteristics and quality with MP3 files. It is believed that a compressed WMA audio file with a bit rate of 160 kbit / s is fully consistent with the quality of an MP3 file with a bit rate of 256 kbit / s. Today, even Apple devices support the WMA format.