Warship
Types and classes: The main types of warships today are, in order of decreasing size: aircraft carriers – amphibious assault ships – cruisers – destroyers – frigates – corvettes – fast attack boats. A more extensive list follows:

Amphibious warfare ships are warships employed to land and support ground forces, such as marines, on enemy territory during an amphibious assault.
Amphibious assault ship is a type of amphibious warfare ship employed to land and support ground forces with ship-deployed helicopters and V/STOL aircraft on enemy territory by an amphibious assault.
Amphibious transport dock is an amphibious warfare ship, that embarks, transports, and lands elements of a landing force for expeditionary warfare missions.
Dock landing ship is an amphibious warfare ship with a well dock to transport and launch landing craft and amphibious vehicles.
Landing craft are small and medium seagoing watercraft, such as boats and barges, used to convey a landing force (infantry and vehicles) from the sea to the shore during an amphibious assault.
Landing Craft Utility is a type of landing craft used by amphibious forces to transport equipment and troops to the shore. They are capable of transporting tracked or wheeled vehicles and marines from amphibious assault ships to beachheads.
Landing Craft Mechanized is a landing craft designed for carrying vehicles during amphibious assaults.
Landing ship, tank is the naval designation for ships first developed during World War II to support amphibious operations by carrying tanks, armoured fighting vehicles, transport vehicles, cargo, and landing troops directly onto shore with no docks or piers.
Landing Craft Support were two distinct classes of amphibious warfare vessels used by the United States Navy during World War II to support landing crafts.
Armed merchantman is a type of merchant ship equipped with naval guns, usually for defensive purposes, either by design or after the fact. In the days of sail, piracy and privateers.
Armed yachts were modified yachts that were armed with weapons and were typically in the service of a navy.
Balloon carrier was a type of ship equipped with a hot-air balloon tied to the ship with a rope or cable, which was used for observation. This type of ship was later replaced by the seaplane carrier.
Cottonclad warships were steam-powered warships with bales of cotton lining as armour used in the American Civil War. The armaments consisted of a ram, random numbers of different cannons and sharpshooters.
Dispatch boats were small boats, and sometimes large ships, tasked to carry military dispatches from ship to ship or from ship to shore or, in some cases from shore to shore. Dispatch boats were employed when other means of transmitting a message was not possible or safe or as quick.
Aviso, a kind of dispatch boat
Brig of War is a brig armed for use by a navy.
Anti-submarine warfare carrier is a type of small aircraft carrier whose primary role is as the nucleus of an anti-submarine warfare hunter-killer group.
Capital ship, the largest and most important ships in a nation's fleet. These were previously battleships, battlecruisers, and aircraft carriers, but the first two warship types are now no longer used.
Aircraft carrier, a warship primarily armed with carrier-based aircraft.
Fleet carrier is an aircraft carrier designed to operate with the main fleet of a nation's navy.
Light aircraft carrier is an aircraft carrier that is smaller than the standard carriers of a navy.
Escort carrier, also called a "jeep carrier" or "baby flattop" is a slow type of aircraft carrier  used during WWII.
Battlecruiser, a ship with battleship-level armament and cruiser-level armour; typically faster than a battleship because the reduction in armour allowed mounting of more powerful propulsion machinery, or the use of a more slender hull shape with a lower drag coefficient.
Battleship, a large, heavily armored warship equipped with many powerful guns. A term which generally post-dates sailing warships.
Ironclad battleship, battleships built before the pre-dreadnought in the late 1850s to the early 1890s.
Pre-dreadnought battleship, sea-going battleships built to a common design before the launch of dreadnoughts, between the mid-1880s to the early 1900s. Pre-dreadnoughts commonly featured a mixed main battery composed of several different caliber guns.
Dreadnought, an early 20th-century battleship, which set the pattern for all subsequent battleship construction. Dreadnoughts differ from pre-dreadnoughts in that they feature an all-big-gun main battery. The advantage lies in that if all the big guns have the same characteristics, only one firing solution will be needed to aim them all.
Fast battleships were battleships which emphasized speed without – in concept – undue compromise of either armor or armament
Bomb vessels were wooden sailing ships which carried mortars instead of cannons.
Coastal defence ship, a type of cruiser-sized warship built for the purpose of coastal defense.
Commerce raider, any armed vessel—privately or government-owned—sanctioned to raid a nation's merchant fleet.
Merchant raiders are disguised commerce raiders.
Corvettes were small ships during the age of sail. The concept was revived again in WWII as a merchant convoy escort and anti-submarine ship. They were only used by the Royal Navy and the Royal Canadian Navy. Today they are used for anti-submarine warfare and patrolling.
Cruiser, a fast, independent warship. Traditionally, cruisers were the smallest warships capable of independent action. Along with battleships and battlecruisers, they have largely vanished from modern navies.
Armored cruiser was a type of warship of the late 19th and early 20th centuries. It was designed like other types of cruisers to operate as a long-range, independent warship, capable of defeating any ship apart from a battleship and fast enough to outrun any battleship it encountered
Scout cruiser  was a type of warship of the early 20th century, which were smaller, faster, more lightly armed and armoured than protected cruisers or light cruisers, but larger than contemporary destroyers. They were used for scouting.
Protected cruiser is a type of naval cruiser of the late-19th century, gained their description because an armored deck offered protection for vital machine-spaces from fragments caused by shells exploding above them.
Torpedo cruiser is a type of cruiser that is armed primarily with torpedoes.
Unprotected cruiser was a type of naval cruiser in use during the early 1870s Victorian or pre-dreadnought era.
Heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 in) caliber; its parameters were dictated by the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930.
Pocket battleship
Light cruiser is a type of small or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck.
Large cruiser is the class of the battlecruiser-sized Alaska-class cruisers of the United States Navy during World War II.
Guided missile cruisers are cruisers armed anti-ship missiles.
Aircraft cruiser (also known as aviation cruiser or cruiser-carrier) is a type of warship that combines the features of the aircraft carrier and a surface warship, such as a cruiser or battleship.
Destroyer, a fast and highly maneuverable warship, traditionally incapable of independent action. Originally developed to counter the threat of torpedo boats, they are now the largest independent warship generally seen on the ocean.
Guided missile destroyer are destroyers armed with anti-ship missiles.
Destroyer escort was the United States Navy mid-20th-century classification for a 20-knot (37 km/h; 23 mph), warship designed with the endurance necessary to escort mid-ocean convoys of merchant marine ships similar to frigates.
East Asian warships
Geobukseon (literally Turtle ship) were wooden sail and oar propelled Korean warships armed with cannons.
Panokseon (literally board roofed ship) were a type of Korean wooden warships propelled by both sailing and rowing armed with cannons and Hwacha multiple rocket launchers.
Atakebune were wooden oar propelled 16th Century Japanese warships armed with few cannons, arquebusiers, and archers. They were mostly bulky floating fortifications.
Mengchong (literally Covered Assaulter) was a type of leather-covered assault warship used in the 2nd and 3rd centuries CE in China.
Louchuan (literally Tower Ship) was a type of warship used as a floating fortress in Ancient China. The Louchuan was meant to board troops onto enemy ships. Although they were also armed with trebuchets for ranged combat.
Wugongchuan (literally Centipede Ship) was a Chinese oared vessel of the 16th century inspired by the Portuguese galley.
Fast attack crafts are a small, fast, agile, offensive, often affordable type of warships armed with anti-ship missiles, guns or torpedoes.
Fire ship, a vessel of any sort set on fire and sent into an anchorage or fleet with the intention of causing destruction and chaos. Exploding fire ships are called hellburners.
Frigate, originally a medium-sized sailing ship.