Cloud gaming is a type of online gaming that renders games on a remote server instead of your local device. That game is then streamed to your device while your input on the controller (or mouse and keyboard) is sent to the server. Or more colloquially, playing a game remotely from a cloud.
Currently, there are three types of consumer services:
Game streaming allows direct and on-demand video streaming of games onto computers, consoles, and mobile devices, similar to video on demand, through the use of a thin client. The actual game is stored, executed, and rendered on the remote operator's or game company's server and the video results are streamed directly to a consumer's computers over the internet.
P2P "cloudless" gaming lets client devices communicate directly back and forth without first reaching an intermediary server. The critical difference from cloud gaming is that game is executed on an actual PC and it is streamed on one-to-one basis.
Progressive downloading or file streaming, deploys a thin client in which the actual game is run on the user's gaming device. A small part of a game, usually less than 5% of the total game size, is downloaded initially so that the gamer can start playing quickly. The remaining game content is downloaded to the end user's device while playing.
One place for all the ways we play.
Stadia lets you instantly enjoy games in up to 4K on your TV without a console. You can also play across laptops, desktops, Pixel 3 and Pixel 3a with cross-screen early access from day one
No waiting for game downloads
Source: The Platform Website.