How To Protect Gmail Or Facebook From Hackers?

Login to your gmail account .and go to Acount
Click On Account after signing in
In your Account Go to Security option
In Security you see whether 2 step verification is
OFF if then turn ON that option for that you
should click on edit
Now It shows as given below. In that click on
Start Setup >>
Now enter your mobile number and click on Send
Code
A code will be received in your phone as a text
message. Enter the code in the sapce provided
and click on Verify
After verifying you can set a default device means
we can login from that device without any code. if
you need to login from other devices a code is
send to your phone. You can login only after
entering the code only. If your phone is lost you
can change the number from your gmail account
by signing in from the default device.