.m4a is the generic extension for audio‑only MP4 files. Inside, you will typically find AAC or ALAC streams plus metadata for chapters, cover art, and lyrics. The format provides gapless playback, efficient compression, and wide ecosystem support. Apple coined .m4a in 2001 to distinguish music downloads from copy‑protected .m4p tracks sold on the iTunes Store. Because MP4’s audio profiles required no licence fees, many podcasters and game developers adopted .m4a for better quality than MP3 at the same bit‑rate. Today .m4a is recognised by Android, Windows, and most car infotainment systems.