How to Reboot my iPhone
Rebooting your iPhone is very easy and if you reboot your iPhone then none of your data will be erased. Just follow the steps below:-
1. Hold the sleep/wake button until the red slider appears.
2. Slide the red slider and your iPhone and your device will be completely turned off.
3. Again hold your sleep/wake button until the Apple logo appears. It will take a few seconds to reboot.