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. Please unlock your screen and hold down power button.
2. There should appear menu with few options similar to this:
3. Now you have to select Reset or Reboot option.
4. And that's it. Your device will restart and should work faster from now on.