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.
WebM is an open multimedia file format developed by Google's IT giant. It was first introduced by the developer on May 19, 2010 at the Google I / O conference. Typically, WebM files store video with compression using VP8 technology, as well as audio with compression using Ogg Vorbis compression. The initial developer of VP8 technology is ON2, which Google later acquired. WebM format provides efficient compression and high quality video. The format is supported by Google Chrome, Mozilla Firefox, and Opera. When installing the necessary codecs in Windows, this format is also supported in Internet Explorer.