A carrier group is any group of ships assigned to a carrier. Usually there are only six carriers out to see at a time, though carriers can steam on their own. The US currently, with the commissioning of the Ford, has eleven super carriers and nine amphibious assault ships. Not many considering at the end of WWII, the US had ~99 carriers of all types commissioned and about another 25 on the books.

The service life of a super carrier is around 50 years.