In architecture, a turret (from Italian: torretta, little tower; Latin: turris, tower) is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification. As their military use faded, turrets were used for decorative purposes, as in the Scottish baronial style.
A turret can have a circular top with crenelations as seen in the picture at right, a pointed roof, or other kind of apex. It might contain a staircase if it projects higher than the building; however, a turret is not necessarily higher than the rest of the building; in this case, it is typically part of a room, that can be simply walked into – see the turret of Chateau de Chaumont on the collection of turrets, which also illustrates a turret on a modern skyscraper.
A building may have both towers and turrets; turrets might be smaller or higher but turrets instead project from the edger of a building rather than continue to the ground. The size of a turret is therefore limited, since it puts additional stresses on the structure of the building. Turrets were traditionally supported by a corbel.
Starting with ships such as USS Monitor and continuing into the present day, a turret was a round chamber situated either on the deck or on another level, that turned about and usually contained ranged weaponry. Jet fighters and helicopters may also have turrets, also Lancaster bombers and B17's.