Bluetooth is a way for different devices to communicate with each other wirelessly. First developed by Ericsson, then formalized in 1999, it works by sending data via a secure, low-cost short-range radio frequency. Bluetooth phones, as you call them, use this technology to communicate with wireless headsets and other devices; PCs with Bluetooth can talk to printers or keyboards and mice, while handhelds can talk to each other without any wires.