I’ve seen a number of people ask what the need of an AppleTV or Hub in a HomeKit setup is for, this article sheds some light on a few terms and what exactly the AppleTV is used for.

Hub

Apple refer to both the AppleTV and HomePod as as a hub and are required if you want to have either remote control of your setup, or for automations to work. The hub is connected via your iCloud account and acts as an always on device. This is what allows your automations to run when you are away from home, and also as a kind of tunnel for remote access.

It’s important to note, even if you can control a HomeKit enabled device remotely via that devices app, i.e Philips Hue, you will still need an Apple hub if you want to control this via HomeKit.

Bridges

A bridge is a device that connects a proprietary communication protocol with HomeKit. For example Philips Hue uses the Zigbee protocol to control lighting. An iOS device doesn’t have a Zigbee radio, so in order to be able to ‘talk’ to each other, the Hue bridge acts as a translator.

Platforms such as Lightwave or Tado will need a bridge to allow such control. Technically, the bridge is the only HomeKit certified product from these vendors.