https://www.macrumors.com/guide/homekit/
"What is HomeKit?
HomeKit is Apple's smart home platform, which is designed to let you control various internet-connected home devices -- ranging from thermostats and plugs to window blinds, light bulbs, and more -- with Apple devices.
These days, more and more products are internet connected, which is why you've heard the phrase "Internet of Things."
The Internet of Things is a confusing mix of "smart" products that connect to the internet and can be controlled by a range of different platforms, from Amazon's Alexa to Google Home to Samsung SmartThings.
HomeKit is Apple's "Internet of Things" solution that connects HomeKit-enabled smart accessories together in a way that lets you operate them using your Apple products."