Convert mv4 to xvid

What is the difference between .mv4 and .xvid?

Description: M4V is a video container that stores audio and video data used for iTunes files. Files of this type may be protected from illegal viewing and copying with Apple FairPlay DRM. In this case audio or video files should be bought in iTunes store. Not protected files can be viewed almost in any modern player because the format is based on MPEG-4 structure.; Xvid-encoded video files are digital video files that have been compressed and encoded using the Xvid codec, an open-source video codec designed for compressing video data in order to facilitate faster transmission over computer networks or for more efficient storage on computer disks. Xvid, which is a reverse spelling of "DivX," emerged as a popular format due to its ability to compress video files without significant loss of quality.