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.
AVI is a video file format developed by Microsoft. The Video for Windows package, within the framework of which the AVI format appeared, was developed by this company in November 1992. It was intended for the operating system Windows 3.1. Since then, for a quarter of a century, the AVI format has remained the main one for storing video files in all versions of Windows operating systems. The name of the format is an abbreviation of the full name Audio Video Interleave File. The format is used to store video data encrypted using a variety of codecs. AVI files, as a rule, use much less compression in comparison with similar formats.