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.
mp3 First released in 1995 and developed by the Fraunhofer Society, the mp3 audio format is arguably one of the most recognizable audio file format that ever existed. This digital audio encoding format hails from the lossy data compression algorithm family. The format enjoys widespread support and compatibility with most handheld music players, smartphones, computers, and in car stereos most of which have native support for the format. It is also a popular format used for distribution of audio files over computer networks such as the internet. Free mp3 encoders such as LAME and audacity give authors the tools necessary to create .mp3 files.