Bluetooth is a wireless technology standard that allows exchange of data over short distances between fixed and mobile devices. It was named after the 10th century Danish king Harald Bluetooth who united Scandinavia, just as Bluetooth intended to unite the PC and cellular industries. While Bluetooth radiation is a type of low-power microwave radiation, long-term exposure has been linked to health risks like cancer and brain tumors. Bluetooth Low Energy was developed to reduce power consumption and allow devices to operate for years on small batteries, finding applications in health monitors, sensors, and transportation.