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