"Wired mode" for Magic Keyboard with Numeric Keypad

I understand that the Magic Keyboard with Numeric Keypad is wireless and that it can be recharged with the included lightning cable in the box. My question is though:

When the keyboard is connected to the iMac via the lightning cable, is it acting in a "wired" mode as opposed to a wireless mode? Or is it always transmitting data wirelessly through Bluetooth? I was wondering if I could just keep the keyboard plugged in with the lightning cable and just use it in a "wired" mode all the time. Thanks.