THE BLUETOOTH RADIO built in to your Mac makes it easy to connect compatible devices wirelessly, and is usually switched on by default. If not, head to System Prefs > Bluetooth and click the Turn Bluetooth On button to activate it.
You can also see whether Bluetooth is active at a glance - and which devices are using it - from the menu bar. To do so, make sure the “Show Bluetooth in menu bar” option in System Preferences > Bluetooth is selected.