The Bluetooth feature built into most A/V receivers (or Bluetooth adapters) is to allow a portable device such as a phone or tablet to stream music to that receiver. This way you can listen to your digital music or streaming apps like Pandora or Spotify from your phone through your main speaker system.
An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints.[1][2] It is embedded as part of a complete device often including hardware and mechanical parts.
An embedded device is an object that contains a special-purpose computing system. The system, which is completely enclosed by the object, may or may not be able to connect to the Internet. Embedded systems have extensive applications in consumer, commercial, automotive, industrial and healthcare markets.