The primary difference between M4V and MP4 is that M4V files are optionally encrypted by Apple’s FairPlay DRM technology. But as diametrically opposed to MP4, another similar format, iTunes M4V container format, developed by Apple Inc., is able to be played only on Apple-approved devices or players. These are the reasons why MP4 is so ubiquity and widely welcome. As such, MP4 format can be payable on any portable devices without any obstacles. With the unexceptionable compatibility, MP4 is not only used to store videos and audio tracks, but also aims to store subtitles and images. A separate hint track is used to include streaming information in the file.Based on the QuickTime format specification, MP4, published in 2001, is a digital multimedia contain format, which is one of the most popular and universal video format in the digital market. Most kinds of data can be embedded in MPEG-4 Part 14 files through private streams. A FairPlay-protected M4V file can only be played on a computer authorized (using iTunes) with the account used to purchase the video. Unauthorized reproduction of M4V files may be prevented using Apple's FairPlay copy protection. Like most modern container formats, it allows streaming over the Internet.

MPEG-4 Part 14 or MP4 is a digital multimedia format most commonly used to store video and audio and store other data such as subtitles and still images. Apple uses M4V to encode video files in its iTunes Store. The primary difference is that M4V files may optionally be protected by DRM copy protection. The M4V file format is a video container format developed by Apple and is very similar to the MP4 format.

International Organization for Standardization

M4v to mp4 converter online