A Bluetooth receiver is a device that allows non-Bluetooth audio equipment to receive audio signals wirelessly from Bluetooth-enabled devices, such as smartphones or tablets. It connects to speakers, headphones, or car stereos, enabling them to play music or other audio without the need for physical cables. These receivers typically plug into the audio input of the device they are connecting to, using a standard audio jack or other connectors. Once paired with a Bluetooth source, they can transmit sound, making it easy to enjoy music from devices like smartphones or laptops on older audio systems.