Lock or unlock your smartphone
You can lock the screen to avoid pressing it or making calls accidentally and, if you have set a BlackBerry® smartphone password, you can also lock your smartphone with a password.
Depending on how you or your administrator set your password options, if you don't use your smartphone for a certain period of time, your smartphone might lock with a password automatically.
key on the top left of your smartphone. 
icon.
key on the keyboard.Next topic: Turn on or turn off airplane mode
Previous topic: View a location on a map