The iPad Sleep/Wake button is the small, black button at the top right-hand corner of the iPad. It is one of the few hardware buttons on the iPad and is primarily used to put the iPad to sleep or to wake it up. Because it is used to put the iPad into a suspended mode, the Sleep/Wake button is sometimes referred to as the suspend button or the hold button.
In addition to putting the iPad to sleep or waking it up when you are ready to use it, the Sleep/Wake button is used to reboot the iPad by holding it down for several seconds. Once held down, the iPad will respond by requesting you to verify by sliding power off button across the screen. After the iPad has fully powered down, it can be turned back on by pressing the Sleep/Wake button again.