It's the default audio format for Apple products, Nintendo products, Android, Blackberry, PlayStation, and many in-dash music systems in cars. M4A files sound better than MP3 files when encoded at the same bit rate due to some of the enhancements.
It was generally intended as the successor to MP3 and the file quality is better and file sizes smaller compared to MP3 files.
M4A audio files were developed to enable easy sharing of digital music, audiobook content, podcasts.
