Using Bluetooth® technology, your iMac can wirelessly connect with devices such as the Magic Keyboard, Magic Mouse, Magic Trackpad, AirPods, peripheral devices, wearable sport accessories, and more.
Before you connect a Bluetooth device with your Mac for the first time, you need to pair them. When a Bluetooth device is paired with your Mac, you can connect or disconnect it using the Bluetooth , then click the control to turn Bluetooth on or off. Your iMac comes with Bluetooth turned on.
Tip: You can add the Bluetooth icon Use Bluetooth devices with Mac in the macOS User Guide.