Google Home Finally Adds Support For Buttons (theverge.com) 1
Smart buttons are physical, programmable switches that you can press to trigger automations or control devices in your smart home, such as turning lights on or off, opening and closing shades, running a Good Night scene, or starting a robot vacuum. A great alternative to voice and app control when you want to control multiple devices, smart buttons are often wireless and generally have several ways to press them: single press, double press, and long press, meaning one button can do multiple things.