What if I update my Iphone when it's jailbroken?

I want to jailbreak my Iphone, I currently have the Iphone 5. I've heard that the jailbreak does not work on ios 6.1.3 Right now I have ios 6.1.2 I want to know what will happen If I jailbreak my phone and then update to 6.1.3 after a while. I just want to experience having the awesome looking tweaks

What does that even mean? (jailbroken)

It will brick if you jailbroke with evasion

It will unbrick it