With the ever-growing popularity of Bluetooth devices many people find themselves wondering how they actually work. Picture a phone connected to a wireless speaker, which will be equipped with Bluetooth hardware and software. The hardware could be an antenna-equipped chip that sends and receives signals on a certain frequency. The software installed on each device will be able to read those signals and resend them to other devices, in a way that they can be understood.
So going back to the phone and wireless speaker, the phone will know how to send audio files and packets of information, in a way that the speaker will be able to understand. For instance, you could use the phone to change the level of the volume on the speaker or even change the track.