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.
FLV is a video file format developed by Adobe Systems. The name is an abbreviation of the full name Flash Video File. FLV format video files are Flash-compatible and usually contain various metadata (titles, audio, video, etc.). FLV-files are widely spread on the global network, in this format they make streaming video for YouTube, MySpace and other video hosting sites. Compared with similar formats, video files have a higher compression ratio. FLV files are easily converted to more common video formats.