Navy/Legends

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.

In a rare occasion, some spaceships were shaped like ancient traditional maritime vessels, such as the wooden-hulled battleship

Space Navies
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.

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 navy. Ex. Eclipse being the reborn Palpatine's flagship.
 * Capital Ships – The designation of "capital ship" referred to the size of a vessel. Capital ships measure 100m or longer. There is 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 tactical weaknesses in the 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 medical frigate 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.

Maritime Navies
Four major categories of most aquatic vessels are generally common among the Galaxy:
 * The basic type of ships were used to transport people or objects between lands.
 * During wars, attack ships, called Destroyers, were invented in order to attack the transports and weaken the enemy's army.
 * The existence of the destroyer required the countermeasure of the Frigates that would protect transport convoys.
 * The next implementation were Cruisers that attacked ground units, followed by anti-aircraft vessels that protected the navy from aerial attacks.

The Gungans and the Selkath were among the most notable species to utilize a seaborne navy.

Behind the scenes
The usage of the word 'navy' or other naval terms (ship, frigate, corvette, cruiser, fleet, admiral, captain etc) which were inherited to space or stellar technology is not uncommon in science fiction works, such as Star Trek. Note that squadron is a term used in real life both for navy and aeronautics.

According to the encyclopedia of Star Wars: Galactic Battlegrounds, space navy evolved from sea navy, although this evolution would have happened as early as 200,000 BBY.