AVI audio/video interleave Next time you see a video clip on your PC, there's a good chance that it's an AVI file. AVI is the file format used by Video for Windows, one of three video technologies used on personal computers. (The others are MPEG and QuickTime.) In AVI, picture and sound elements are stored in alternate interleaved chunks in the file. See also: .mov, MPEG, QuickTime, Video for Windows