Would anyone be able explain the difference between the Corleonesi Clan and the cosca/famiglia in Corleone? I read that they are two separate entities

Did they merge? Was the cosca/famiglia in Corleone absorbed by the Corleonesi Clan? Or wiped out?

Or maybe I’m misunderstanding...was Leggio and co. a part of the Corleone cosca/famiglia and then expand it into the Corleonesi Clan?

Is Messina Denaro considered to be a part of the Corleonesi? I know he’s from a different part of the island but I also know that the clan had members that were outside of just the town of Corleone.

Thank you to anyone that can explain it and add some clarity for me!