How to Set Up Accessories in HomeKit on Your iPad
You have to set up your accessories in the HomeKite app on your iPad. Accessories are the lights, door locks, automated window shades, switches, thermostats, sensors for temperature and intrusion, and other items that do the work of HomeKit. They are manufactured by various manufacturers, and, if they are compatible with HomeKit, Apple certifies them with this logo.
Accessories communicate with HomeKit wirelessly. Some accessories (the Philips Hue bulbs and other devices, for example) communicate wirelessly to a small device that in turn connects to HomeKit. The device is normally called a hub or bridge and it may come with a starter kit of your first bulbs. Other manufacturers sell accessories that include bridge-type functionality: iDevices sells accessories that don’t require an external bridge.
Once you add an accessory directly to HomeKit, you can add it to rooms, scenes, and your home. If you use a bridge, you add the bridge itself to a room or scene, and then its accessories become available. Whether added directly or via a bridge, accessories work the same way with HomeKit.