The power button turns off the console.
Usage
When you are down with the console, press the button to turn it off. When you do this, you will be asked if you really want to turn on the console. Click OK or press the button again.
Holding the button down kills the power just like any other computer, and just like any other computer this should only be done if the system is not responding
On Keyboard
is not mapped to any key. If you are running EOS on a laptop, you can just close the application, or shut off the laptop.