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.
AMR is a sound file format with a specific focus. Created a long time ago, before the advent of MP3. some sources call the developer Ericsson. The name of the format is an abbreviation for Adaptive Multi Rate. Sound files of this format are intended for mobile devices and in GSM cellular networks. Using this format provides a small file size due to the technology of signal coding in the speech frequency range. Effectively compressing audio recordings of human speech makes this format often used in voice recorders on mobile phones, for voice recordings, and for MMS messages.