As someone in the tech area and likes PC gaming, I know nothing about Stadia or GeForce Now, despite having a 3070 and a Shield. Was stadia its own platform an

As someone in the tech area and likes PC gaming, I know nothing about Stadia or GeForce Now, despite having a 3070 and a Shield. Was stadia its own platform and hardware? I thought it was a way to say, play steam games over the net on an x11 session or something. I'm not being silly, I really had no idea how the thing worked.