A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon

Artillery

Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...

 and at the same time lets the weapon be aimed and fired in many directions.

The turret is also a rotating weapon platform. This platform can be mounted on a fortified

Fortification

Fortifications are military constructions and buildings designed for defence in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs...

 building

Building

In architecture, construction, engineering, real estate development and technology the word building may refer to one of the following:...

 or structure

Structure

Structure is a fundamental, tangible or intangible notion referring to the recognition, observation, nature, and permanence of patterns and relationships of entities. This notion may itself be an object, such as a built structure, or an attribute, such as the structure of society...

 such as an anti-naval land battery

Land battery

A land battery is a special type of gun emplacement or anti-shipping naval interdiction fortification used in coastal defense to protect areas such as anchorages, harbors, and rivers...

, or on an combat vehicle

Combat vehicle

A combat vehicle, also known as a ground combat vehicle, is a self-propelled, weaponized military vehicle used for combat operations. Combat vehicles can be wheeled or tracked.- Automation :...

, a naval ship

Naval ship

A naval ship is a ship used for combat purposes, commonly by a navy. Naval ships are differentiated from civilian ships by construction and purpose...

, or a military aircraft

Military aviation

Military aviation is the use of aircraft and other flying machines for the purposes of conducting or enabling warfare, including national airlift capacity to provide logistical supply to forces stationed in a theater or along a front. Air power includes the national means of conducting such...

.

Turrets may be armed with one or more machine gun

Machine gun

A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....

s, automatic cannons

Autocannon

An autocannon or automatic cannon is a rapid-fire projectile weapon firing a shell as opposed to the bullet fired by a machine gun. Autocannons often have a larger caliber than a machine gun . Usually, autocannons are smaller than a field gun or other artillery, and are mechanically loaded for a...

, large-calibre

Caliber

In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....

 guns, or missile launcher

Multiple rocket launcher

A multiple rocket launcher is a type of unguided rocket artillery system. Like other rocket artillery, multiple rocket launchers are less accurate and have a much lower rate of fire than batteries of traditional artillery guns...

s.