Admiral Rank Insignia
Starfleet Admiral is a military rank, the equivalent of which is used by the service organizations of many civilizations. As a traditional naval grade, Admirals command fleets of ships, as opposed to Captains commanding single ships or units. Many rank systems, including that used by various incarnations of Starfleet, have been known to use several grades of the Admiral rank, which include, in order from most senior: Fleet Admiral, Admiral, Vice Admiral, Rear Admiral and Rear Admiral Lower Half.
In comparison to other ranking systems, this rank is equivalent to the ground-based rank of General, or the Cardassian Union's quasi-military rank of Legate.