Advanced Audio Coding is a family of audio compression technologies used in many media systems. A player needs support for the particular encoding arrangement supplied by the source, and playback can also depend on container and output handling. An AAC label describes audio encoding rather than programme language, speaker layout or the quality of the original recording.
A practical example
A television app may decode an AAC audio track internally and send ordinary audio to the television speakers. A different source can use another AAC profile or track arrangement, so an app's broad format support is not a full description of every possible stream.
A common misunderstanding
Do not assume that every silent programme has a volume problem. Confirm the selected track and supported encoding before changing unrelated network or account settings in response to missing sound.
Related terms
Stable technical definition. Editorial approach