It is becoming more and more frequent to hear about 'Facebook account hacks'and is that this social network is vulnerable to security, that an attacker who knows his victim very well, can easily go to the option Forgot your password? And follow the steps to change the access email, recognizing photos of your friends and other security requirements.
It is in this sense that I am going to tell you about an option of facebook security, that few use and that goes unnoticed by many, but that is extremely necessary for strengthen your Facebook account at every login.
1. In the upper right menu, go to the option 'Account settings'
2. In the left panel choose 'Security' and later 'Login approvals'.

Check the option "Request a security code to access my account from unknown browsers”, What follows is to define a name for the device you are using (PC, phone) and finally enter a phone number in case you have not done it before to receive notifications.
You will receive an SMS to confirm that you do have access to the mobile with a code, enter the code and voila! ... you will have a extra layer of security every time you log in from an unknown browser.
What is login approval?
First you have to make it clear that an unknown browser is a computer or phone that you have not used before. Login approvals are a additional level of security that your phone uses to protect your account.
How Does It Work?
When logging in from an unknown browser, you will need a security code, which you can only get from your phone through an SMS you will receive. By entering the code, you can prove that it is really you who is trying to log in and log in securely.
La login approval, It is very useful if you usually connect from internet cafes, school or university or third-party computers.