This is a very old cathedral or "Dom", built in two different eras in the Romanesque style. Inside it is very dark and oppressive. Apart form the statue of the "Bamberger Ritter", or Knight, there is little else to see here. Just keep moving and don't plan too much time here.
There are many phenomenal buildings and places to see in this beautiful city- this, IMHO, just isn't one of them!