During the past 10 years, Bluetooth has become the de facto technology for wireless point-to-point connectivity. Bluetooth 4.0 (BT4.0) is the latest revision that was introduced by the Bluetooth Special Interest Group (BT-SIG) in June 2010. It includes three specifications in one single standard:
Classic Bluetooth: Bluetooth 2.1 + EDR (enhanced data rate).
Bluetooth High Speed (HS): Bluetooth 3.0 + HS.
Bluetooth Low Energy (LE): This is the new technology that is introduced in BT4.0.