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.
aac The advanced audio coding audio format or AAC format for short is a standardized audio encoding format designed to succeed the popularized mp3 format. It is the result of the collaborative efforts of several companies including bell labs, Nokia, and Sony among others. It was initially released in 1997 as part of the lossy digital audio compression family of audio encoding formats. AAC enjoys a wealth of native compatibility and support by different platforms, hardware, and software applications including video game consoles such as the PlayStation 3, Nintendo DSi, and platforms such as Android, and YouTube. Today even diverse hardware such as in dash car audio players have native support for the format.