A crew, in a military and/or starship context, refers to those who complete the tasks involved in operating a ship or installation. Usually, members of the crew have specialized areas, and, these specialized areas are usually grouped into separate divisions. For example, on Starfleet ships, three main divisions exist: command division; operations division; and sciences division. These divisions can be split further.
A crew also is comprised of officers and other crew, although these individuals work together in a chain of command, the top usually being referred to as a commanding officer. An all-encompassing term used for this group is crewmembers.