This capability is built within devices, so there's no need for any other data transmission ... the internet and stream media ...

The ways wireless Bluetooth transmission can be used are defined in "profile" specifications, and the major profiles are summarized below. See Bluetooth. Supports mono and stereo audio.

Transmitting stereo signals via the Bluetooth protocol from a smartphone, tablet or other audio source to a powered sound system (boombox, stereo receiver, car system, etc.). Bluetooth audio is ...