Captain

Captain and Chief officer are overlapping terms, formal or informal, for the commander of a military unit, the commander of a ship, airplane, spacecraft, or other vessel, or the commander of a port, fire department or police department, election precinct, etc. Captain is a military rank in armies, navies, coast guards, etc., typically at the level of an officer commanding a company of infantry, a ship, or a battery of artillery, or similar distinct unit. Chief officer may be used interchangeably with captain in some situations, as when a Captain-ranked Navy officer is serving as the commander of a ship. The terms also may be used as an informal or honorary title for persons in similar commanding roles.

The term "captain" derives from katepánō (Greek: κατεπάνω, lit. "[the one] placed at the top", or " the topmost") which was used as title for a senior Byzantine military rank and office. The word was Latinized as capetanus/catepan, and its meaning seems to have merged with that of the Italian "capitaneus" (which derives from the Latin word "caput", meaning head). This hybridized term gave rise to the English language term captain and its equivalents in other languages (Capitan, Kapitan, Kapitän, El Capitan, Il Capitano, Kapudan Pasha etc.)

https://en.wikipedia.org/wiki/Captain