Bluetooth is an industrial specification for wireless personal area networks
(PANs). Bluetooth provides a way to connect and exchange information between
devices such as mobile phones, laptops, personal computers, printers, GPS
receivers, digital cameras, and video game consoles over a secure, globally
unlicensed short-range radio frequency. The Bluetooth specifications are
developed and licensed by the Bluetooth Special Interest Group. Bluetooth is a standard and communications protocol primarily designed for
low power consumption, with a short range (power-class-dependent: 1 meter, 10
meters, 100 meters) based on low-cost transceiver microchips in each
deviceBluetooth enables these devices to communicate with each other when they
are in range. The devices use a radio communications system, so they do not have
to be in line of sight of each other, and can even be in other rooms, as long as
the received transmission is powerful enough.

Class
Maximum Permitted Power
mW(dBm)Range
(approximate)
Class 1
100 mW (20 dBm)
~100 meters
Class 2
2.5 mW (4 dBm)
~10 meters
Class 3
1 mW (0 dBm)
~1 meter
Computer requirements
A personal computer must have a Bluetooth adapter in order to be able to communicate with other Bluetooth devices (such as mobile phones, mice and keyboards). While some desktop computers and most recent laptops come with a built-in Bluetooth adapter, others will require an external one in the form of a dongle.
Unlike its predecessor, IrDA, which requires a separate adapter for each device, Bluetooth allows multiple devices to communicate with a computer over a single adapter.


USB bluetooth adapter works for short-range wireless data connectivity between PC computers and bluetooth enabled devices. (eg. cellular phone, PDA).