m4v M4V is a file format developed by Apple for the iTunes store's content and is very similar to the MP4 file extension. M4V is supported exclusively by Apple devices. Other video formats like MP4 and MOV can be converted to M4V in order to run on Apple devices. The most common difference between the M4V and MP4 formats is that M4V offers DRM-Copyright Protection which prevents the copyright of media content. To play a DRM-protected M4V file the computer needs authorization by opening the iTunes account used for buying the media file. However, if the files are not protected by DRM, the user can just rename the file extension from M4V to MP4 in order for it to be recognized by non-apple devices.
mov The .mov multimedia format is a MPEG-4 video container commonly associated with Apple's QuickTime framework. It is the movie file format most commonly praised for bringing feature length in-color movies to the Macintosh with the initial release of QuickTime in 1991. This was before anything comparable was available for the personal computer and Microsoft Windows operating system. This movie format supports multiple sequences of data or tracks categorized into audio, video, effects, and text such as subtitles. A .mov file is considered a resource file. Thus it may or may not be final i.e. it may be self-contained where all video frames and or audio samples are within the file or it may refer to external sources such as other files or data streams using movie references.