A Navy was a military unit composed of various vessels and was commonly known as a Starfleet or a Defense Fleet. Though several worlds and civilizations used the word "Navy" as traditionally associated with a fleet of sea vessels, the majority of the the Galaxy primarily used it to define a fleet of starships.
Numerous worlds built space navies for their own defense as well as for use by galactic governments in times of peril. Prominent civilizations that were known for their contributions to the advancement of starfleets were Mon Calamari and Kuat. Some spaceships were shaped like ancient traditional maritime vessels, such as the Fairwind, though this was rare.
A Naval task force would normally include:
- Flagship – this ship was the formal head of a naval task force, and usually the seat of power for the senior officer in command of the fleet. This was usually the most powerful ship in the fleet it commanded.
- Capital ships – the designation of "capital ship" referred to the size of a vessel. Capital ships measured 100m or longer. There was no upper limit on capital ship size. (Ex: a Corellian Gunship measured a mere 120m and was considered a capital ship, while an Executor-class Star Dreadnought measured 19,000m and was also classified as a capital ship).
- Support Ships – These vessels were usually smaller capital ships such as frigates and light cruisers used to compensate for the tactical weaknesses of larger vessels (Ex: the Lancer-class frigate was covered in anti-starfighter weaponry to protect larger warships with little anti-fighter capabilities) and/or to augment the firepower of larger vessels (Ex: in the Imperial Navy, two Strike-class cruisers were considered the equivalent of one Victory-class Star Destroyer and were used as such). These ships also encompassed other support roles such as medical vessels (Ex: The Rebel Alliance Fleet's primary hospital ship during the Galactic Civil War was a EF76 Nebulon-B escort frigate called the Redemption).
- Transports – these were used primarily as cargo or personnel carriers (Ex: The Bulk transport saw heavy use with the Rebel Alliance Fleet as a troop transport during the Galactic Civil War).
- Starfighters – Fighters were small one- or two-man (sometimes three as in the case of the ARC-170) vessels used for the protection of the fleet, reconnaissance, and anti capital ship actions.