Stadia is Google’s foray into game streaming. You purchase the Stadia controller and, if you plan to play on your TV, a Google ChromeCast. The Stadia controller connects to your TV via ChromeCast wirelessly over WiFi. At the moment, in order to play on your phone, tablet or PC, you have to have the controller connected via a USB-C cable.
Once you’ve connected the controller to a screen, you’ll use the Stadia app on your phone to start playing games. Well, you’ll use the app to switch back and forth between your phone and TV and any other non-PC device. To play on PC you go to the Stadia website and login there, and once you’ve plugged in a controller you can start playing.
So, for instance, I was able to start playing Red Dead Redemption 2 on my HP Spectre x360 and then, mid-game, unplug the controller and walk over to my TV where I used my phone to start playing it there instead, and then I was able to switch directly over to my phone after that.
In some ways, Stadia is like the Nintendo Switch in this regard. You can play a game “docked” to your TV or you can take it with you on your phone or laptop.
Unlike the Switch, Stadia games don’t download to any of these devices. They’re all streamed via the cloud. This is also handy, in some respects, since you don’t have to waste precious storage space on all these devices. You don’t need a traditional “console” to hook up to your TV, just the much less expensive ChromeCast which is part of the Stadia Premiere package that costs $129—significantly less expensive than any modern console.