The bluetooth headset is a wireless headset based on the bluetooth technology.
The bluetooth techonology is a standard for wireless short distance radio communications.
Devies like a headset and a mobile phone can communicate with each other without wires within
approximaterly 10 meters.
Bluetooth headset is a qualified bluetooth headset that complies with the bluetooth 1.1 or 1.2
protocol. It supports two profiles : Headset Profile and Hands -free profile.
It will work with any qualifiled  bluetooth device that supports the headset profile or the hands-free
profile.
Your bluetooth headset will allow you to take a call , initiate a call (if your phone has voice controls).
and adjust volume directly on your headset, without the need to touch your mobile phone.