Quick guide
About AVI and MP3 files
AVI - Audio Video Interleave
AVI is an older Microsoft video container that still appears in many archives and camera exports. Converting AVI can make older videos easier to play and share.
MP3 - MPEG-1 Audio Layer III
MP3 is a compact audio format that works almost everywhere. It is a good choice when you want a small file for music, voice recordings, podcasts, or sharing audio online.