Identifying Bosses

Can someone tell me the difference between monster infrequents, bosses, nemesis bosses and superbosses and how to tell the difference?

Monster infrequents are items that drop from specific type of monsters, both normal and bosses.
Nemesis bosses have their name in red text, are much tougher than regular bosses and have a nemesis chest near their spawn. Check http://grimdawn.wikia.com/wiki/Creatures to find more info about them. There’s also info about boss rarity.
Maybe someone else can clarify superbosses.