Aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a naval force to project air power worldwide without depending on local bases for staging aircraft operations. Aircraft carriers are expensive to build and are critical assets. Aircraft carriers have evolved from converted cruisers to nuclear-powered warships that carry numerous fighter planes, strike aircraft, helicopters, and other types of aircraft.
There is no single definition of an "aircraft carrier", and modern navies use several variants of the type. These variants are sometimes categorized as sub-types of aircraft carriers, and sometimes as distinct types of naval aviation-capable ships. Aircraft carriers may be classified according to the type of aircraft they carry and their operational assignments. Admiral Sir Mark Stanhope, former head of the Royal Navy, has said that "To put it simply, countries that aspire to strategic international influence have aircraft carriers".