Destroyer (DD/DDG)

A destroyer is a fast, multi-mission medium surface combatant that screens larger ships against air, surface, and submarine threats. In US hull classification DD denotes a gun-armed destroyer and DDG a guided-missile destroyer; the line evolved from the torpedo-boat destroyers of the 1890s. The modern type ship is the Arleigh Burke class (DDG-51, in service from 1991) with the Aegis combat system and 96 Mk 41 VLS cells. The plain DD designation is now largely historical, the missile-armed DDG having replaced it in front-line fleets.