M4A and OGG 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.
OGG here means Ogg Vorbis, a royalty-free lossy codec that predates Opus. It is competitive with AAC and remains common in games.
- Where M4A files come from
- iTunes purchases, Apple Music downloads, voice memos and audiobooks.
- Where OGG is used
- Game audio, Spotify's older streams and open-source projects.