On/Off Button
Press the On/Off button to turn off the device’s screen. You can still take calls, play music, and receive notifications
with it off, but the screen stays blank until you wake it by pressing this button or the Home button. To turn
the device off, hold the On/Off button down until the screen dims and the red ‘slide to power off’ slider appears.
Slide your finger across the switch, and the iPhone powers down. (To turn your device back on, press and hold
this button again until the Apple logo appears.)
You can also decline or silence calls, alerts, and alarms with the On/Off button; press it once to silence an incoming
alert or call; press it twice in succession to send the caller to voicemail.