dv .DV is a file extension that provides for digital video cameras. This file extension is utilized by home and professional camcorders alike. It is the standard file format that prevails over other alternative video file formats. No other file format can stand up to the quality and utility of the .DV file extension and its other related file extensions, .DVCAM and .DVCPRO.
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.