By unrooting your phone you return your phone to the stock. Unroot is the opposite of root. You can unroot your phone for security reasons.
1. Open "SuperSu".
2. Go to "Settings".
3. Click on "Full Unroot".
4. Now, click on "Continue".
5. Wait for some time until all the process gets done.
6. Now, your phone will restart.
7. After restarting, your phone is unrooted. Enjoy!