From left to right: iPhone SE (1st generation), iPhone 8, and iPhone X and later
On iPhone 6 and later, and on iPhone SE (2nd generation) and later, press the side button to wake your iPhone or put it in sleep mode. On iPhone SE (1st generation) and earlier, press the button on the top.
Use the ring/silent switch to mute sounds and alerts.
If orange is displayed on the switch, it means your iPhone is in silent mode and will vibrate for incoming calls or alerts. When in silent mode, the alarms you've set in the Clock app will still sound and calls from your Favourite contacts will still ring.
Use the volume up/down buttons to adjust the volume when you're listening to music, watching videos or playing games.
When you press the buttons, you'll see the Volume under the indicator. When you're not using other apps, the buttons will adjust the ringer volume and you'll see Ringer under the indicator.
Home button/Touch ID
Use the Home button to unlock your device or make purchases using Touch ID. Press the Home button once to go to the Home screen. Press the Home button twice to bring up the App Switcher.
On iPhone X and later, and on iPhone SE (3rd generation), press and hold the side button and one of the volume buttons to restart your iPhone. On iPhone SE (2nd generation) and iPhone 8, 7 or 6, press and hold the Side button. On iPhone SE (1st generation) and earlier, press and hold the button on the top.
Press and hold the Side button or Home button to use Siri.