To save battery power, you set up your computer so that when you press the power button, your computer goes into standby mode: a low power state that saves your work and quickly returns you to your desktop when you power up your computer again. You also select a power scheme that automatically puts your computer in standby mode after being idle for a certain period of time. That way, if you forget to manually put the computer on standby, it will automatically go into standby after it has been idle for a specified amount of time.