Both MP4 and AVI are container formats, that is, MP4 and AVI are wrappers for video codec, audio codec and other files. ... MP4 is based on MOV as a lossy format using MPEG4 AVC/H.264 codec. It is the reason why many people believe AVI is better in quality than MP4. But actually AVI file can also carry MPEG-4 video.WMV is principally for online streaming just like RealVideo's formats while AVI is best use for high quality playback on PCs and editing purposes. 4. There are many codecs and file extensions associated with AVI while WMV is a proprietary standard drafted by Microsoft.Encoded with the same codec MPEG-4, MP4 is similar to MOV. Actually, MP4 was developed on the basis of MOV file format. Both are lossy and can be used in the QuickTime environment. ... However, there are some slight difference between these two formats.Usually, MKV has a larger size than AVI or other common video formats. A large hard drive is necessary. MKV is also a formats that allows you to enjoy perfect quality 3D video. DVDFab can help you to enjoy Blu-ray and DVD Movies better with the output video of AVI and MKV.Because of their almost identical nature, the MPEG-4 format can be used by both the MOV and MP4 container formats. In spite of the fact that MOV was intended for QuickTime player and MP4 uses the same lossy compression standards, they are mostly interchangeable in a QuickTime-only environment.