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.
MP4 is an abbreviation for MPEG-4 Part 14. It can also be called MPEG-4 AVC. In this case, the abbreviation AVC (Advanced Video Coding) is an advanced video encoding. By the name of the format, it is easy to guess that it is necessary for working with video files. The format was first proposed in 1998. Since then, MP4 is considered one of the most common file formats used to store and transmit multimedia. MP4 is a container format that provides the ability to combine audio, video, subtitles and pictures in one file. It is also suitable for posting rich content. Say three-dimensional graphics, menus and interactive features. There are many portable players and other devices that play MP4. For this, a PC or laptop is also quite suitable. The MP4 format is a robust application that needs relatively low performance. And therefore, users could use such a tool for their own purposes. This tool has found wide application, as the technology for the production of more and more powerful devices, both portable and desktop with a large hard drive capacity, is constantly evolving. Due to the fact that the speeds of various types of connections to the global network are increasing, MP4 has become more affordable. It acts like the MP3 format, although it is more complex. The format compresses files and remains high-quality.