M4A came from MPEG-4 Audio, is an extension used mostly by Apple in iTunes.
But what to do when we have few or a lot of .m4a files and we want the same files/music available in the most popular MP3 format?
Follow these steps to convert your files from M4A to MP3.
Download and install M4a to MP3 Converter - is free - from this page.
Add files from your computer.
Select desired format for files that will be generated with this tool.
You have now desired files saved on your computer, with MP3 format.
This application also supports .aac, .m4r and other audio formats as input.