HomeKit™ is Apple's home automation platform for controlling smart home products using iOS apps and Siri® voice commands. HomeKit is automatically included in the operating system of all iPhone, iPad and iPod Touch devices with iOS 8 or later.
The iDevices Connected app on iOS devices is a HomeKit aggregator, meaning it will show and allow you to control any device that is HomeKit compatible (door locks, lights, etc.). The HomeKit platform allows changes to be made across the entire platform. For example, if you change the name of a product in the iDevices app, it will change in any app for HomeKit products such as the Apple Home app.
When a product is setup in the iDevices app, it’s automatically connected to Siri through the HomeKit Platform. You can say things like, “Hey Siri, turn on my Switch!” and Siri will turn it on for you!