It’s a portable device to play PC games. It is powered by a Valve implementation of a Linux System to run, develop and emulate Windows or Linux (aka. PC) games. It has all the bells and whistles for anyone to play basically any game decently (at hardware and featureware level, like touchscreen, trackpads, gyroscope, light sensors and extra buttons to custom commands). Since it is based on a Desktop platform, you can implement almost anything that you would normally do on a PC station, such as run software or emulate games from other platforms and consoles.

tldr; comfortable portable console.