There are a number of essential differences between aircraft designed to operate from carriers and those designed to operate solely from land bases. Some of the features are detrimental to good structural weight and even to aerodynamic performance, and involve both the aircraft and carrier in special equipment.

Of these features the two most important are assisted take–off and deck landing. Assisted take–off includes catapulting, accelerating and rocket assistance; landing involves arresting and safety–barriers.

It is now the practice to refer to all methods of mechanically–assisted take–off as catapulting, to bring it into line with American terminology. Until recently, catapulting denoted a particular method of launching whereby the aircraft was supported entirely on a cradle with no part of the airframe in contact with the ship structure, and such equipment was installed in ships with no flight deck. Accelerating denoted that the aircraft was launched along the deck on its own undercarriage which gave it some degree of support. Accelerating was peculiar to ships with flight decks, i.e. carriers.