Following a lengthy search (a process beginning in ignorance and ending in confusion); I purchased a smartphone, the Android 4.0 Galaxy Nexus . An expensive choice, but luck (and a family member’s generosity) was with me. This phone was added as an extra line on a family plan which, in addition to available specials, significantly reduced the cost. Once the phone was in my sweaty little hands, the first step was to address security issues by locking the phone and installing antivirus. This article takes a look at phone lock. Click here  to read the article on antivirus.
As many functions–including phone lock–are found in Settings, a shortcut was added for easier access. To do this, open Apps and–with a long press on the Settings icon–drag it to the home screen.
To lock the phone, in Settings, scroll down and tap Security. In Security, tap Screen lock.
Lock choices are, according to the manual, “listed in the approximate order of the strength of their security, starting with None and Slide, which provide no security”.
Slide was the default, but I chose Password (not available in all Android phones).
A password of at least 4 digits is required. It should be easy to use, but hard to decipher. A difficult balance.
Tap Automatically lock to set the amount of time before the phone locks.
The PIN option setup is very similar to Password.
For Face Unlock, your photographed image (unlike the caricature below) is used to unlock the phone. This option requires a backup method, in case an image is unavailable.
Pattern Unlock has been a feature in Android phones from the beginning. For that, a pattern is created by tracing a route through a series of dots. Repeating that pattern is then required to unlock the phone.
Note: If music is playing when the phone locks, it will continue to play and the Play and Pause controls will remain functional.