A guided-missile destroyer (DDG) is a destroyer whose primary armament is guided missiles so they can provide anti-aircraft warfare screening for the fleet. Most modern destroyers are of the guided-missile type, and they are widely deployed by advanced navies; in particular, the Arleigh Burke-class guided-missile destroyer is the most numerous class of warship in the US Navy.
Guided-missile destroyers are equipped with large missile magazines, with modern examples typically having vertical-launch cells. Some contain integrated weapons systems, such as the United Statesâ Aegis Combat System, and may be adopted for use in an anti-missile or ballistic-missile defense role. This is especially true for navies that no longer operate cruisers, so other vessels must be adopted to fill in the gap.
Many guided-missile destroyers are also multipurpose vessels, equipped to carry out anti-surface operations with surface-to-surface missiles and naval guns, and anti-submarine warfare with torpedoes and helicopters.
The NATO standard designation for these vessels is DDG, while destroyers which have a primary gun armament or a small number of anti-aircraft missiles sufficient only for point-defense are designated DD. Nations vary in their use of destroyer D designation in their hull pennant numbering, either prefixing or dropping it altogether.
Although the French Navy no longer uses the term "destroyer", the largest frigates are assigned pennant numbers with flag superior "D", which designates destroyer.