Commander

A Commander was a military rank.

In Imperial Service
In the Imperial Navy, a Commander was a command-level rank given authority over a wide area of operations and personnel. Aboard a Star Destroyer, a Commander typically managed a major sector of the warship's operations. A Commander could also be the Star Destroyer's Executive Officer or Third Officer.

In most cases, Commanders were the closet aids to the Captain. On a smaller vessel, a Commander could be the Commanding Officer, or Executive Officer, depending on the situation.

In the Imperial Starfighter Corps, a Commander was a Wing Commander, given command over several squadrons aboard a warship or station.