Light aircraft carrier in the context of "Escort carrier"

The Battle of the Coral Sea, from 4 to 8 May 1942, was a major naval battle between the Imperial Japanese Navy (IJN) and naval and air forces of the United States and Australia. Taking place in the Pacific Theatre of World War II, the battle was the first naval action in which the opposing fleets neither sighted nor fired upon one another, attacking over the horizon from aircraft carriers instead. It was also the first military battle between aircraft carriers.

To strengthen their defensive position in the South Pacific, the Japanese decided to invade and occupy Port Moresby (in New Guinea) and Tulagi (in the southeastern Solomon Islands). The plan, Operation Mo, involved several major units of Japan's Combined Fleet. Two fleet carriers and a light carrier were assigned to provide air cover for the invasion forces, under the overall command of Admiral Shigeyoshi Inoue. The U.S. learned of the Japanese plan through signals intelligence and sent two U.S. Navy carrier task forces and a joint Australian-American cruiser force to oppose the offensive, under the overall command of U.S. Admiral Frank J. Fletcher.

A helicopter carrier is a type of aircraft carrier whose primary purpose is to operate helicopters. It has a large flight deck that occupies a substantial part of the deck, which can extend the full length of the ship like HMS Ocean of the Royal Navy (RN), or extend only partway, usually aft, as in the Soviet Navy's Moskva class or in the Chinese Navy's Type 0891A. It often also has a hangar deck for the storage and maintenance of rotorwing aircraft.

Pure helicopter carriers are difficult to define in the 21st century. The advent of STOVL aircraft such as the Harrier jump jet, and now the F-35B, have complicated the classification; the United States Navy's Wasp class, for instance, carries six to eight Harriers as well as over 20 helicopters. Only smaller carriers unable to operate the Harrier, and older, pre-Harrier-era carriers, can be regarded as true helicopter carriers. In many cases, other carriers, able to operate STOVL aircraft, are classified as "light aircraft carriers". Other vessels, such as the Wasp class, are also capable of embarking troops such as marines and landing them ashore; they are classified as landing helicopter docks.

A landing helicopter dock (LHD) is a multipurpose amphibious assault ship that is capable of operating both as a helicopter carrier and as a dock landing ship. LHD vessels are built with a full-length flight deck similar in appearance to a light aircraft carrier to operate VTOL rotorcrafts such as utility/attack helicopters, tiltrotor aircraft (such as the MV-22 Osprey) and VSTOL fixed-wing aircraft (such as the AV-8 Harrier and the F-35B Lightning II), as well as a well dock for launching landing crafts and amphibious vehicles. Some recent designs, such as the Chinese Type 076 class, even support CATOBAR operations for light aircraft and UCAVs via aircraft catapults and arresting gears.

The United States Navy (USN) and the Royal Australian Navy (RAN) use the term as a specific hull classification symbol. Examples of this kind of ship include the USN's Wasp class, French Navy's Mistral class and ships of the Spanish Navy's Juan Carlos I class including those designs based on the class, such as the RAN's Canberra class. Other nations also use the designation for their vessels, such as the Republic of Korea Navy for its Dokdo class. The Type 075 and Type 076 classes of the People's Liberation Army Navy (PLAN), though only regarded as amphibious assault ships in their native China, are considered LHDs in NATO reporting names.

A fleet carrier is an aircraft carrier designed to operate with the main fleet of a nation's navy. The term was developed during World War II, to distinguish it from the escort carrier and other less capable types. In addition to many medium-sized carriers and supercarriers, some light carriers are also classed as fleet carriers.