Greeze is probably orthodox not catholic. There is a difference, but I'm not sure what other than they don't report to the Pope, and they do recognize the pope (and vise versa)
There are dogmatic differences such as the Filioque, where one Church says that the Holy Spirit proceeds from the Father only, whereas the other claims that it also proceeds from the son.
It's kind of like the systemd rageforks, only for sillier (unless you're religious, I guess) reasons:
