Captain Nyoko Honda
Captain Rank Insignia
It is most often held by starship and starbase commanders, as well as adjutants and executives serving beneath admirals. This rank is usually considered a big transition, because it is often the first rank in which officers run a base of operation (for example, a starship) more or less by themselves. The equivalent ground forces rank to Starfleet Captain is Colonel.
On rare occasions, a Captain will be placed in temporary command of a taskforce or fleet. In these cases, this Captain is referred to as a "Fleet Captain", and has operational command normally reserved for Flag Officers. Visiting Captains aboard another starship are referred to as "Commodore" to prevent confusion during starship operations.
It should also be noted that there are rare cases of officers holding the Captain's rank have served other than the commanding officer of starship. Examples include "Captain of Engineering" Montomery Scott, who never actually served as a permanent ship's captain.