Just have a few questions. Ubuntu Backports

Hi! I bet everyone is using Ubuntu backports? Is it totally safe to enable it?
Well, if so, How do you activate the Ubuntu Backports? It will just update
the old software between releases right? Or does it apply anything else?
I think I can find out how by reading the ubuntu document about backports,
just wanted to ask to be sure that it is totally safe and that it will not affect
my system in a bad way.
Thanks!

https://help.ubuntu.com/community/UbuntuBackports

A full explanation of backports is in the above wiki, together with an explanation of each of your questions and concerns