Turning Off an iPod
To turn off an iPod, press and hold down the Play/Pause button for a second or two. The iPod screen will turn off. You can turn off the iPod from any screen, regardless of whether anything is playing or not.
iPods really have two Off modes. When you use the Play/Pause button to turn an iPod off, you are really putting it to sleep. In the Sleep mode, the iPod's screen is dark, and it will pause any content that is currently playing. In Sleep mode, the iPod uses less battery power than when it is awake or playing audio, photos, or video. You should put your iPod to sleep whenever you aren't actively using it.
After it's been in Sleep mode for a time, the iPod will power itself down. This shuts down all the tasks currently running and stops the iPod's disk. This is the lowest energy state.
You'll be able to tell in which mode an iPod has been by the amount of time it takes to respond to your pressing one of its controls. If it responds immediately and picks up right where you left off, the iPod was asleep. If you see the Apple logo instead, the iPod was powered all the way down and needs to restart. The Apple logo will be displayed on its screen during this process. After a few moments, you'll see the Main menu, and your iPod will be ready for action.