Steam in-home streaming allows you to play a game on one computer when the game process is actually running on another computer elsewhere in your home. Through Steam, game audio and video is captured on the remote computer and sent to the player’s computer. The game input (keyboard, mouse or gamepad) is sent from the player’s computer to the game process on the remote computer.
Any two computers in a home can be used to stream a gameplay session and this can enable playing games on systems that would not traditionally be able to run those games. For example, a Windows only game could be streamed from a Windows PC to a Steam Machine running Linux in the living room. A graphically intensive game could be streamed from a beefy gaming rig in the office to your low powered laptop that you are using in bed. You could even start a game on one computer and move to a more comfortable location and continue playing it there.
I’m seriously curious about what the performance is going to be like.