I'm not sure what the exact differences are, The 8C is probably on a higher deck. At some point in the lettering scheme B, C, D it becomes an aft or corner Balcony that isn't a suite sized cabin but is bigger than a standard balcony. Maybe one of our resident experts can help.
However, just for information purposes, recently Carnival changed their category numbers. John Heald posting the chart below.
It's just the new name for a Cat 12 per Jim's list. However, on my booking info at the Carnival site it still says Cat 12.
Dave, they haven't changed the names on Carnival.com yet either. Just when I get all the re-categorizations figured out, they go and change the names. Hopefully, they'll get it all in order on the site and confirmations soon.
Just book on Miracle Mar 12 and the categories were confusing. Now it all makes sence. Had to take a Cat 7a Obstructed view as this cruise is nearly sold out of any cat balcony. Very strange, wonder why this is so popular.