M4A and WAV explained
M4A is an MP4 container holding only audio — usually AAC, sometimes Apple Lossless. The extension exists mainly so players know not to look for a video track.
WAV stores uncompressed PCM audio — the raw samples, exactly as captured. A stereo CD-quality minute is roughly 10 MB, which is the price of having no compression whatsoever.
- Where M4A files come from
- iTunes purchases, Apple Music downloads, voice memos and audiobooks.
- Where WAV is used
- Recording sessions, sample libraries and audio editing.