Samsung Galaxy J3 Prime User Manual page 22

Lock or Unlock Your Device
Use your device's screen lock features to secure your device.
By default, the device locks automatically when the screen times out.
To lock the device:
► Press the Power key.
The default Screen lock on your device is Swipe. To choose a more
secure screen lock, see "Set a Screen Lock" on page 172.
To unlock the device:
► Press the Power key or Home key, and then drag your finger across
the screen.
Restart the Device
If your device stops responding to taps or finger gestures and you are
unable to turn it off, you can restart your device.
► Press and hold the Power key and the Volume down key at the
same time for more than seven seconds.
Set Up Your Device 14