Anything “smart” needs to be able to receive instructions. Hue smart lights use Zigbee or Bluetooth to communicate, depending on whether you have a Bridge.
Philips Hue with Bluetooth
The simple start to smart lighting and can control up to 10 lights.
This setup doesn’t require a Bridge, so you use your mobile device to communicate directly with the lights.
Philips Hue with Bridge
Unlock the full experience and control up to 50 lights.
The Bridge connects to your router to establish a Zigbee network. Each light is a repeater of the signal, meaning that you can extend the network by adding lights. This is called a mesh network.