Setting screen lock is for the Samsung Galaxy Y or any touch screen phone and tablet is an essential thing needed to prevent accidental pressing of the screen and to secure the contents of your Android gadget from unwanted views and usage by other people.
1. Go to settings and press "Location and Security":
2. Press "Set screen lock"
3. Choose between "None", "Pattern", "PIN", and "Password" from the list. For the purpose of this tutorial, we will choose "PIN". For me this is the better way to lock the screen as the PIN can be typed easily and fast compared to password.
5. Confirm your PIN and press OK.
6. That's it. You now have a PIN for your Samsung Galaxy Y. To confirm if the PIN has been done correctly, press the power button to lock the screen then press it again to open. You should see similar to the screenshot below.
You can just repeat the process if you want to change your PIN or the method, either "None", "Pattern", or "Password".