Warship

A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster and more manoeuvrable than merchant ships. Unlike a merchant ship, which carries cargo, a warship typically carries only weapons, ammunition and supplies for its crew. Warships usually belong to a navy, though they have also been operated by individuals, cooperatives and corporations.

In wartime, the distinction between warships and merchant ships is often blurred. In war, merchant ships are often armed and used as auxiliary warships, such as the Q-ships of the First World War and the armed merchant cruisers of the Second World War. Until the 17th century it was common for merchant ships to be pressed into naval service and not unusual for more than half a fleet to be composed of merchant ships. Until the threat of piracy subsided in the 19th century, it was normal practice to arm larger merchant ships such as galleons. Warships have also often been used as troop carriers or supply ships, such as by the French Navy in the 18th century or the Japanese Navy during the Second World War.

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A naval ship is a military ship (or sometimes boat, depending on classification) used by a navy. Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are damage resilient and armed with weapon systems, though armament on troop transports is light or non-existent.

Naval ships designed primarily for naval warfare are termed warships, as opposed to support (auxiliary ships) or shipyard operations.

Naval ship classification
Naval ship classification is a field that has changed over time, and is not an area of wide international agreement, so this article currently uses the system as currently used by the United States Navy.

•     Aircraft carrier – ships that serve as mobile seaborne airfields, designed primarily for the purpose of conducting combat operations by Carrier-based aircraft which engage in attacks against airborne, surface, sub-surface and shore targets.
•     Surface combatant – large, heavily armed surface ships which are designed primarily to engage enemy forces on the high seas, including various types of battleship, battlecruiser, cruiser, destroyer, frigate, and corvette.
•     Submarine – self-propelled submersible types regardless of whether they are employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability.
•     Patrol combatant – combatants whose mission may extend beyond coastal duties and whose characteristics include adequate endurance and sea keeping providing a capability for operations exceeding 48 hours on the high seas without support.
•     Amphibious warfare – ships having organic capability for amphibious assault and which have characteristics enabling long duration operations on the high seas.
•     Combat logistics – ships that have the capability to provide underway replenishment to fleet units.
•     Mine warfare – ships whose primary function is mine warfare on the high seas.
•     Coastal defense – ships whose primary function is coastal patrol and interdiction.
•     Sealift – ships that have the capability to provide direct material support to other deployed units operating far from home base.
•     Support – ships, such as oilers, designed to operate in the open ocean in a variety of sea states to provide general support to either combatant forces or shore based establishments. (Includes smaller auxiliaries which, by the nature of their duties, leave inshore waters).
•     Service type craft – navy-subordinated craft (including non-self-propelled) designed to provide general support to either combatant forces or shore-based establishments.

Size
In rough order of tonnage (largest to smallest), modern surface naval ships are commonly divided into the following different classes. The larger ships in the list can also be classed as capital ships:

•     Aircraft carrier
•     Helicopter carrier
•     Battleship
•     Battlecruiser
•     Heavy cruiser
•     Light cruiser
•     Destroyer
•     Frigate
•     Corvette
•     Patrol boat
•     Fast attack craft

Some classes above may now be considered obsolete as no ships matching the class are in current service. There is also much blurring / gray areas between the classes, depending on their intended use, history, and interpretation of the class by different navies.

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