Google has officially unveiled Project Stream, which is now called ‘Stadia’.
Stadia is a console-less gaming system. All games are streamed from Google’s powerful cloud-based infrastructure. Game processing and hardware are stored in the cloud, and gamers can play AAA games with up to 4K quality using almost anything with a screen (cellphone, computer, TV, etc)
Any USB-controller can be used to play Stadia games, however Google will be releasing a first-party Stadia controller which will give gamers access to Google Assistant while they play.