Codec

A codec (coder-decoder) is the algorithm that encodes audio for storage or transmission and decodes it for playback — MP3, AAC, Opus and FLAC are codecs.

Codecs are distinct from container formats: an .mp4 file (container) usually carries AAC (codec) inside. Compatibility questions are usually container questions; quality-per-bit questions are codec questions.

Related terms

Container formatA container format is the file wrapper that packages encoded audio (and video, captions, metadata) — MP4, MKV,… BitrateBitrate is the amount of data used per second of audio, in kilobits per second (kbps) — the main quality dial … Lossy compressionLossy compression shrinks audio by permanently discarding information judged least audible — the approach of M…