Google Galaxy Nexus Android mobile technology platform 4.0 Users Guide - Manual (Page 13)

11
Use the lock screen
To protect personal information, you can adjust your phone's lock settings:
1 From the Home or All Apps screen, touch the Settings icon .
2 Scroll down and touch Security.
3 Touch Screen lock.
4 Touch the type of lock you'd like to use.
After you set a lock here, a lock screen displays whenever your screen wakes up, requesting the pattern,
PIN, or other specified key.
Important Screen lock options are listed in the approximate order of the strength of their security, starting with None and Slide,
which provide no security. Face Unlock and Pattern provide minimal security, although they can be more convenient
than the stronger options.
If your phone's playing music when the screen locks, you can continue listening or pause the selection
without unlocking.