If you’re just starting your adventure into the world of Apple TV HomeKit, you should understand that a HomeKit home hub acts as a messenger to your other HomeKit accessories via iCloud. This allows you to do things like remotely turn on or off your front porch and indoor lights or live stream from your home security cameras. A HomeKit hub, combined with your Apple ID, gives you secure access through your Mac, iPhone, or iPad, even when you're not on your home Wi-Fi network.