Bluetooth is a wireless technology used to create a Personal Area Network (PAN) capable of transmitting data between low-power devices over a limited range. Bluetooth has become a popular technology in the mobile phone world primarily because it's perfect for connecting a phone to a wireless headset for hands-free calling. The latest Bluetooth protocols also support stereo audio, which means that next-generation cell phones may include digital audio players that connect wirelessly to Bluetooth stereo headsets. Bluetooth is also used to connect cell phones to PCs for file transfers and software upgrades, and to Bluetooth-equipped cars for hands-free calling over the car's audio system.