Soft resets are usually conducted in an attempt to fix malfunctioning applications or because they're required for software installation.
Soft reset contrasts with hard reset, which removes all user data, settings and applications and returns a device to the same state it was in when it shipped from the factory.
1. Let's begin from unlocking your screen and holding down power button.
2. When you will see this menu you can let go of the power button.
3. Now all you have to do is tap on Reboot/Restart option to finish.
4. And now your phone will restart itself so please wait patently. Good job!
Sometimes your phone is not responding due to some application or other problem, in this situation you can reboot your phone.
If you want to erase your all data from your phone then you should go with factory setting restore.
This option will erase your all data.