For questions pertaining to Bluetooth setup, usage and troubleshooting on the Raspberry Pi, whether onboard or via a USB dongle.
Bluetooth is often used for connecting audio devices (speakers, monoheadset with a microphone or a stereo headset without a microphone), keyboards, and mice.
The Raspberry Pi 3 has onboard Bluetooth (a wireless communications standard) connectivity, and on other Raspberry Pis Bluetooth devices may be connected via a Bluetooth hub on one of the board's USB ports. See eLinux.org for a list of adapters that work with Raspberry Pi.
