SteamOS is a independent Linux distribution derived from Debian and created by Valve. SteamOS, like it's name suggests, targets the gaming market. The full screen mode of the Steam client is the default desktop, although booting into GNOME is possible - however due to the system being based on Debian 8, one will run into compatibility issues with modern software. The main purpose of SteamOS is to contact Steam services and download games that run either natively or (more likely) through emulation on a Linux system. All the necessary software (drivers, etc) is included, which allows for a plug-and-play experience. SteamOS is preinstalled on the Steam Deck and earlier Valve hardware.