Developed by Apple, Amazon, Google, and Samsung (and others), Matter is an open-sourced, IP-based connectivity software layer for smart home devices. It works over Wi-Fi, ethernet, and the low-power mesh networking protocol Thread and currently supports over 30 device types. These include lighting, thermostats, locks, robot vacuums, refrigerators, dishwashers, dryers, ovens, smoke alarms, air quality monitors, EV chargers, and more.
A smart home gadget with the Matter logo can be set up and used with any Matter-compatible ecosystem via a Matter controller and controlled by more than one with a feature called Multi-Admin.
Amazon Alexa, Google Home, Samsung SmartThings, and Apple Home are some major smart home platforms supporting Matter, along with hundreds of device manufacturers.