Originally Posted by
SteamDeck On Steam Deck, your games run on a different operating system than the one on your desktop PC. It's a new version of SteamOS, built with Steam Deck in mind and optimized for a handheld gaming experience. It comes with Proton, a compatibility layer that makes it possible to run your games without any porting work needed from developers. For Deck, we're vastly improving Proton's game compatibility and support for anti-cheat solutions by working directly with the vendors. “Hold on to your butts!”
The new version of SteamOS is optimized for handheld gaming, and it won't get in your way with other stuff. But if you want to get your hands dirty, head on out to the desktop.