Quick guide
About M4A and MP3 files
M4A - MPEG-4 Audio
M4A is a common audio format used by Apple devices, music apps, and mobile recordings. It can keep audio quality high while producing smaller files than uncompressed audio.
MP3 - MPEG-1 Audio Layer III
MP3 is a compact audio format that works almost everywhere. It is a good choice when you want a small file for music, voice recordings, podcasts, or sharing audio online.