Bluetooth is a short-range wireless networking technology. Bluetooth is used to link (or pair) two devices, such as smartphones and headsets; cameras and printers; and keyboards and computers. It is sometimes called a cable-replacement technology.
Both devices must support Bluetooth in order to be paired; if they do, though, the pairing is designed to happen automatically, with little to no user interaction.
Bluetooth is considered a networking standard, just like Wi-Fi. But Bluetooth is not a replacement for Wi-Fi, because the primary goal of Bluetooth is to directly link two devices, such as a laptop and a printer. Bluetooth connections are typically limited to about 30 feet. Wi-Fi wireless hotspots, however, can have a range of about 300 feet. And Wi-Fi allows many devices to connect to one network; the technology is often used to provide access to the Internet or to a local network.
Bluetooth wireless technology was named after a Danish Viking and King, Harald Blatand; his last name means "Bluetooth" in English. He is credited with uniting Denmark and Norway, just as Bluetooth wireless technology is credited with uniting two disparate devices.