What is the Difference Between a 'Weak Chin' and Micrognathia/retrognathia and How Do You Know Which One You Have? (photo)

Also, it is common to have a weak chin. The only thing I know for sure is that I have an overbite. I don't have chewing issues or breathing issues and I breathe through my nose throughout the day. My teeth are not squeezed together as sometimes happens when you have the smaller lower jaw issue. So how can I tell which one I have and are you able to tell for sure from just these pictures?