M4V is a video file format that has been downloaded from the Apple iTunes store. The format contains TV shows, videos, films, music. It looks like a .MP4 file, but it sometimes has copy protection when Apple's FairPlay DRM is used (technical copyright protection). The M4V format, i.e., MPEG-4 iTunes Video File, was developed by Apple. MP4 is a container format. Like the same formats as MOV, AVI, MKV, it provides the ability to combine a variety of multimedia streams into one file. Mostly it is audio and video. In order to play the protected M4V file, the computer must be authorized using the iTunes account from which the videos were purchased. In this case, it can be used in order to buy video. Unprotected M4V files can be played by other video players if the extension is changed from .M4v to .Mp4. Files with the M4V extension contain both sound and video data. You can convert M4V files to MP4 format. In this case, it will be possible to play them on other computers, since the M4V files are protected by DRM. MP4 files, compared to the M4V format, do not allow you to specify partition information.
WMA is a widespread licensed audio stream compression format. Created in 1999 by Signal Processing Group, a member of the IT giant Microsoft. Initially, this company created WMA as a competitor to the popular MP3 format. The name WMA is an abbreviation for Windows Media Audio. Among the advantages of this format is the support of almost all Windows systems and devices, as well as the similarity in characteristics and quality with MP3 files. It is believed that a compressed WMA audio file with a bit rate of 160 kbit / s is fully consistent with the quality of an MP3 file with a bit rate of 256 kbit / s. Today, even Apple devices support the WMA format.