A destroyer is a medium-sized warship with missiles, torpedoes, naval guns, etc. as its main weapons and multiple combat capabilities. It is one of the most powerful types of ships in the naval fleet, which is used to attack submarines and surface ships, fleet air defense, as well as escort, reconnaissance patrol vigilance, mine-laying, attack on shore targets, etc.

Among the modern naval vessels, the most versatile and numerous ships are destroyers, which are medium-sized surface ships equipped with a variety of weapons such as anti-air, sea, and submarine, and have a variety of combat capabilities. It has a displacement of between 2000 and 8500 tons and a speed of about 30 to 38 knots. Destroyers can perform combat missions such as air defense, anti-submarine, anti-ship, ground attack, escort, reconnaissance, patrol, vigilance, mine-laying, fire support, and attacking shore targets, and have the title of "all-rounder at sea."

Destroyers are a type of ship that developed with the advent of torpedo boats. In the 60s of the 19th century, a torpedo boat with torpedoes as a weapon appeared, which was small and fast, and could pose a great threat to large enemy ships. To deal with torpedo boats, anti-torpedo boats were built - torpedo gunboats, which were the predecessors of destroyers. Subsequently, the torpedo gunboats, which were constantly updated and equipped to increase their speed, were renamed torpedo boat destroyers, or destroyers for short. It had not only artillery installations, but also torpedo armament, which could be used against enemy torpedo boats and other ships. By the time of the First World War, destroyers were able to sail with fleets. Therefore, the destroyer at that time was also called the "fleet destroyer". Over time, the displacement of destroyers has increased from 400 tons to more than 8,000 tons now; The speed was increased to 38 knots. Most of the new types of naval weapons and equipment have also been equipped with destroyers, and some countries have even built anti-submarine helicopter destroyers.

In the 90s of the 19th century, there was a new advance in steam power units, and the British Navy, according to the advice of A. Yarrow, a shipbuilder alliance, built a warship with strong combat effectiveness and fast speed, which could effectively deal with torpedo boats. In 1893, the destroyers "Havoc" and "Hornett" were launched, with a displacement of 240 tons, a speed of 50 km / h, four naval guns and three torpedo tubes, they were the first destroyers in the world and the fastest warships of their time. Since then, the navies of various countries have built destroyers, increased tonnage, increased firepower, and increased endurance, so that they have stronger combat capabilities.

At the beginning of the 20th century, the displacement of armored ships (i.e., battleships) continued to increase, and destroyers, which were lighter than cruisers, took on the tasks of reconnaissance, patrol, and escort that were originally undertaken by cruisers. During the First World War, due to the massive use of submarines, the role of torpedo boats declined, so destroyers were used more for escort and anti-submarine operations for the fleet, the flotilla. During this period, the destroyer's firepower, speed, endurance and other performance continued to improve, and the displacement also reached more than 1,000 tons.

In World War II, destroyers, which continued to be strengthened, in addition to performing anti-submarine escort duties, also took on more of the task of fleet air defense due to the rise of naval aviation. It also played an important role in supporting operations on the island, transporting personnel and materials, and patrolling bases. He also participated in naval battles between fleets many times and had outstanding performances, so he was called "all-rounder at sea".

After the 50s, destroyers did not decline like battleships and cruisers, but because of their flexibility and versatility, they were valued by the navies of various countries, and rapidly developed in the direction of missiles, electronics, and command automation, and the division of labor between anti-submarine destroyers and air defense destroyers appeared, and the tonnage of destroyers also increased significantly, and the displacement of large destroyers reached more than 6,000 tons, which is equivalent to light cruisers. On some destroyers are also equipped with anti-submarine helicopters.

Missile destroyer - the world's first missile destroyer was the USS Mitchell, built by the United States in 1953, with a displacement of 5200 tons and armed with Tatar anti-aircraft missiles. The first destroyer to be equipped with anti-ship and anti-submarine missiles was the USS Koontz, a guided missile destroyer launched by the United States in 1958. The first nuclear-powered destroyer was the USS Bainbridge, built by the United States in 1962.

Currently, about 30 countries around the world have 400 destroyers.

Cruisers have a variety of combat capabilities, mainly large surface warships operating in the open ocean. The main class of combat ships of the Navy. It is used for offensive and defensive operations at sea, covering aircraft carrier formations and other fleet formations, defending one's own side or destroying the enemy's sea lines of communication, attacking enemy ships, bases, ports and shore targets, providing fire support during landing operations, and serving as the command ship of the sea formation.

The cruiser is equipped with offensive and defensive weapons systems commensurate with its displacement, sophisticated detection and computing equipment and a command-and-control communication system. According to the displacement, it is divided into: light missile cruisers and heavy missile cruisers; According to the power plant, it is divided into: conventionally powered cruisers and nuclear-powered cruisers. Its full load displacement is 0.5~30,000 tons, and the maximum speed is 30~35 knots. It has high speed, large endurance and good seakeeping.

At the end of the 19th century, there were mainly armored cruisers and horizontal armored cruisers. During the First World War, cruisers with a full load displacement of 3000~4000 tons appeared. At the beginning of World War II, there were heavy cruisers (armed with 203 mm guns or more) and light cruisers (armed with 152 mm guns), and later large cruisers with a full load displacement of 27,000 tons and 305 mm guns. In the early 60s of the 20th century, the United States built nuclear-powered missile cruisers. Modern cruisers are generally equipped with ship-to-ship missiles, ship-to-air missiles, new naval guns, anti-submarine weapons, anti-submarine helicopters, new radars, sonars, and so on, constantly improving their anti-submarine and air defense capabilities, equipped with an automated command and control system for ships, and possessing rapid response capabilities.

Cruisers are the one with the most naval guns and missile weapons among the ships currently in service, and they are one of the older types of ships in the navy, and they are mainly used to destroy the enemy's sea lines of communication, join formations to conduct naval operations, protect the existing sea lines of communication, ensure the landing of landing troops, and lay mine obstacles.

A cruiser is a powerful, multi-purpose surface warship that is one of the main combat ships of the modern navy, capable of maneuvering for extended periods of time and in adverse weather conditions. It is equipped with an offensive and defensive weapon system, which has a high speed and a large endurance.

Early cruisers, like battleships, used naval guns as their main armament. With the increasing rise of the air carrier, the cruiser, like the battleship, was declining day by day. And missile weapons and nuclear power units, which were born in the 50s and widely installed on ships, brought the cruiser back to life. In the 50s, the United States was the first to equip cruisers with missile weapons, and later built the world's first nuclear-powered cruiser "Long Beach". And the former Soviet Union has not stopped the construction of large cruisers. France, Great Britain and Germany also paid more attention to the development of cruisers. In this way, by the beginning of the 90s, there were still 9 cruisers in 85 countries around the world.

A battleship, also known as a capital ship and a combat ship, is a large surface warship with large-caliber naval guns as its main weapon, with strong armor protection and assault power, and can fight in the open ocean. In naval battles, it is usually an artillery battle in which multiple ships are lined up in a single column battle line, hence the name. Early battleships were also called ironclad or armored ships.

The name battleship came about with the change in naval tactics during the Anglo-Dutch War of 1655-1667. At that time, the warships with the strongest firepower did not engage in cross-side combat, but formed a column of battle, sailed parallel to the enemy fleet, and used the guns on one side of the fleet to concentrate fire on the enemy volley, hence the name "battleship". The first of its kind, the British ship "Kings of the Seas", built in 1638, had three broadside gun decks and 102 guns. The battleships at this time were all wooden sailing ships.

In 1849, France built the world's first battleship "Napoleon" with a steam engine as the main power plant. It was armed with gunners 100 steam battleships of the era. But it still has sails as auxiliary power. In 1861, Britain's first iron-hulled armored battleship, HMS Warrior, also had auxiliary sails. The sails on the battleship gradually disappeared after 20 years of arrival.

In 1862, France built the first battleship with a rotating turret, the "Prince Albert", and for a time the name of the ship replaced the battleship because the turret-mounted guns became obsolete in any direction.

In 1906, the British-built "Dreadnought", the largest and most powerful armored ship in the world at that time, was launched and the name of the battleship was restored. Designed and supervised by the famous Italian engineer Colonel Cunibedi, the Dreadnought had a displacement of 17,900 tons, a speed of 40 km/h, and was equipped with 10 305 mm main guns, 24 76 mm secondary guns, and underwater torpedo launchers, which were more than twice as powerful as the other largest armoured ships at the time, and the armor of the two sides, turrets and conning towers was up to 280 mm thick. Since then, various naval powers have built their own battleships following the example of the "Dreadnought". Before the 30s of the 20th century, "dreadnought" ships were synonymous with battleships, and the number of battleships also became a criterion for measuring the strength of a country's navy. The last battle column in the world was launched at the end of World War II. During this period, the displacement, speed, caliber of the main guns, the thickness of the armor and other properties of the battleships were greatly improved, and among the hundreds of battleships built successively, all of them inherited the basic form laid by the "Dreadnought".

The largest battleship in the world was the battleships "Yamato" and "Musashi", launched by Japan during the Second World War, with a full load displacement of 72,800 tons, a maximum speed of 50 km / h, and nine guns with three 457 mm guns and shells weighing 1,460 kg, as well as 12 triple 155 mm secondary guns and 12 twin 128 mm flat-height guns. On October 24, 1944, the "Musashi" and "Yamato" were sunk by American planes on the first day of the month in 1945, which marked the decline of the battleship and its place in naval warfare was replaced by aircraft carriers. After the Second World War, countries stopped building new battleships. It is estimated that no country will build battleships in the future.

In the 80s, the United States modernized and converted four decommissioned "Iowa"-class battleships, equipped them with various new radars, missiles, air defense, electronic countermeasures, and command and control communication systems, and reorganized them into active service. In 1989, the United States completed the refit project of the Missouri and the USS Wisconsin, and returned to service, and deployed them in the Pacific and Atlantic Oceans respectively to independently carry out maritime operations and support such tasks as landing and attacking shore targets. During the Gulf War in January 1991, the US military used the battleships "Missouri" and "Wisconsin" to shell Iraqi targets and launch cruise missiles. But then, in 1993, four American battleships were again retired from active service.

The battleship went through two stages: a sail battleship and a steam battleship. Steam battleships appeared in the mid-19th century. At the beginning of the 20th century, Britain built the battleship Dreadnought; France, Russia, Germany, Italy, Japan, the United States and other countries also built battleships one after another. In the early 80s of the 20th century, the United States began to modernize four Iowa-class battleships, which have a full load displacement of about 58,000 tons, a maximum speed of 35 knots, and a cruising range of 15,000 nautical miles when using economic speed (17 knots).