Security to your phone is as essential as securing other personal stuff. Your phone in the hands of wrong person can make you wander around. The security measures which many users avoid are very much helpful. The Android phone is provided with so many security measures to be used. Only you just have to call them. You shouldn’t look around for third party applications to achieve highest level of security on your phone as it comes in stock Android phones.
One of the easiest ways to secure an Android device is to lock your screen with a PIN, password or pattern, and yet more than half of all Android devices remain totally unprotected The good news is that locking your Android device's screen is extremely easy, and will put you ahead of more than half of the current Android population. All you need is a few minutes and a working set of fingers. (Keep in mind, however, that many wireless carriers and manufacturers limit this functionality unless you root your Android device.)
Follow below steps to set pattern lock on your android device –
1. Open Setting and scroll to bottom and now select Security option.
2. Now you can see your Screen lock by default Slide or none selected.
For change pattern lock tap here and select pattern.
After press Continue it will be ask you pattern again for confirmation.
Press Confirm, now you have selected pattern lock on your device.
When you are start your device you can see pattern lock for security purpose.