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. Firstly unlock your device and press and hold power button.
2. Now there should be a menu on your screen similar to this:
3. Select and tap on Reboot or Restart option from the menu.
4. Your phone will now restart itself and hopefully this will fix any problems that you had with your device.