Needless to say, M4A is less popular and widespread than MP3. By comparison, an MP3 file is universally supported. M4A is an unprotected AAC file that you often deal with when download music from iTunes. One downside of an M4A file, especially when compared to an MP3 format, is that it can only be opened by iTunes or Windows Media Player version 12 and later.

As more and more music was consumed on the go via devices such as iPods and smartphones, the need for small file sizes became greater, which is why an M4A file has grown in popularity and importance. M4A files tend to be encoded using an AAC codec and are small in size because they have been compressed - often providing a smaller file-size footprint than an MP3 file format, while mirroring, if not improving, the quality of an MP3 file. An M4A file is the go-to audio format for compressed audio, due to the creation and popularity of iTunes.

It was developed by Apple, largely as a result of the popularity of the MP3 file. An M4A file format is also called an MPEG-4 audio file, and is an audio file saved in the MPEG-4 standard.

Convert itunes downloads m4a to mp3