Bluetooth is named after the Danish King Harald Bluetooth who was respnsible for uniting Scandinavian Europe of Norway and Denmark and brought Christianity there.
This Bluetooth Technology is a wireless technology which whorks at 2.54GHz frequency. It is a peer to peer communication of limited range of distance. Commercially it is available in Class 1 and Class 2 categories. Class 1 covers 100 metres and class 2 covers 10 mts.
It has many profiles say Audio Gate way (phone), Audio handsfree(Mobile Handsfree or Headset), Human interface device (keyboard, mouse), Fax, Imaging, File Transfer, Serial port Profile, LAN etc. The data rate is 750KBps.
The disadvantage of Bluetooth is the power consumption, which drains battery very quickly.
In the same frequency range (2.54Ghz other tehcnologies are ZigBee and WiFi(WLAN)

ZigBee is a very low power wireless communication lasting even a coin battery for a few years. But its data rate is only 250KBps and hence suited only for data transmi ...more

Bluetooth wireless technology makes it possible to transmit signals over short distances between telephones, computers and other devices and thereby simplify communication and synchronization between devices. It:

eliminates wires and cables between both stationary and mobile devices;
facilitates both data and voice communication;
offers the possibility of ad hoc networks and delivers the ultimate synchronicity between all your personal devices.

Hi Priya,
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, PCs, printers, digital cameras and video game consoles via a secure, globally unlicensed short-range radio frequency. The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group.

# - Bluetooth is a wireless protocol for sending audio and video data between mobile computers, laptops, hand held computers, PDAs and bluetooth enabled devices such as print servers etc.
# - A short range wireless specification that allows for radio connection between devices with in a 30 foot range of each other.
# - It mostly used in cell phones, either using a bluetooth headset or frm transfering data from phone to computer.
# - It's a very good mode of transfering data without any hesitation.
# - And also it does not require high bandwidth.

Regards
Durga

to share files like data,music,picture, etc by wireless instrument called bluetooth

Bluetooth wireless technology is a short-range communications system intended to replace the cables connecting portable and/or fixed electronic devices.
The system offers services that enable the connection of devices and the exchange of a variety of data classes between these devices

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, PCs, printers, digital cameras and video game consoles via a secure, globally unlicensed short-range radio frequency. The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group.

Bluetooth is a radio standard and communications protocol primarily designed for low power consumption, with a short range (power class dependent: 1 metre, 10 metres, 100 metres) based around low-cost transceiver microchips in each device.

Bluetooth lets these devices 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, so long as the received transmission is powerful enough.

Class Maximum Permitted Power
(mW) Maximum Permitted Power
(dBm) ...more

u could search google for a better answer.

Bluetooth is a radio standard and communications protocol primarily designed for low power consumption, with a short range (power class dependent: 1 metre, 10 metres, 100 metres) based around low-cost transceiver microchips in each device.

Bluetooth lets these devices 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, so long as the received transmission is powerful enough.

Class 1 100 mW 20 dBm ~100 meters
Class 2 2.5 mW 4 dBm ~10 meters
Class 3 1 mW 0 dBm ~1 meters

Bluetooth is a low-power-consumption and short-range wireless technology for personal area networks (PANs). It connects your personal electronic devices, such as laptops, mobile phones, digital cameras, audio equipments, and printers, without the clutter of cables. The Swedish telecom giant Ericsson originally developed Bluetooth. The name is inspired by King Harold Bluetooth, known for his unification of previously warring tribes from Denmark, Norway, and Sweden. Likewise, the Bluetooth technology was intended to unify and connect different personal electronic devices.