Bluetooth is a wireless technology standard used for exchanging data between fixed and mobile devices over short distances using short-wavelength UHF radio waves in the industrial, scientific and medical radio bands, from 2.402 GHz to 2.480 GHz, and building personal area networks (PANs). It was originally conceived as a wireless alternative to RS-232 data cables.
There are two important parameters of Bluetooth devices - class and supported profiles.
"Class" signifies the distance at which a Bluetooth connection is possible. Most mobile devices are Class 2, which means they have a range of up to 10 m. Class 1 devices are rare and have a range of up to 100 feet.
A "profile" is a type of Bluetooth connection. The most common are the Headset (HSP) and Handsfree (HFP) profiles that enable the device to connect to a wireless headset or handsfree.
Some other profiles are OBEX (OBject EXchange) which allows transfer of files, contacts and events; A2DP, which adds support for streaming of stereo sound and AVRC, which allows remote control of playback.