A destroyer is a smaller warship that uses its speed to protect larger and less maneuverable vessels in a fleet against smaller attackers. It was a light ship originally developed for protection and later, after the widespread impact of the submersible warship, otherwise known as the Submarine. The Destroyer was smaller than a Battleship, though it had enhanced antisubmarine and antiaircraft capabilities, which also made it less effective in ship-to-ship combat, since it was designed to focus on the other two targets.