Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to connect and exchange information between devices like personal digital assistants (PDAs), mobile phones, laptops, PCs, printers and digital cameras via a secure, low-cost, globally available short range radio frequency.
Bluetooth is a radio standard primarily designed for low power consumption, with a short range (power class dependent: 10 centimetres, 10 metres, 100 metres or up to 400 metres [1], ) and with a low-cost transceiver microchip in each device.
Bluetooth lets these devices talk to each other when they come in range, even if they are not in the same room, as long as they are within up to 100 metres (328 feet) of each other, dependent on the power class of the product. Products are available in one of three power classes:
1. Class 1 (100 mW) [still readily available]: It has the longest range at up to 100 metres (328 ft).
2. Class 2 (2.5 mW) [most common]: It allows a quoted transmission distance of 10 metres (33 ft).
3. Class 3 (1 mW) [rare]: It allows transmission of 10 cm (3.9 in), with a maximum of 1 metre (3.3 ft).
for more info, pls refer to
wikior
www.bluetooth.com