Tank
With World War II the multi-turreted tanks proved impracticable, and as the single turret on a low hull design became standard, crews became standardized around a crew of four or five. In those tanks with a fifth crew member, usually three were located in the turret (as described above) while the fifth was most often seated in the hull next to the driver, and operated the hull machine gun in addition to acting as a co-driver or radio operator. Well-designed crew stations, giving proper considerations to comfort and ergonomics, are an important factor in the combat effectiveness of a tank, as it limits fatigue and speeds up individual actions.
Tank
A tank is an armoured fighting vehicle designed for front-line combat, with heavy firepower, strong armour, tracks and a powerful engine providing good battlefield maneuverability. The first tanks were designed to overcome the deadlock of trench warfare in the 1910s; they are a mainstay of modern ground forces and a key part of combined arms combat. Modern tanks are versatile mobile land weapon system platforms, mounting a large-calibre cannon in a rotating gun turret, supplemented by mounted machine guns or other weapons. They combine this with heavy vehicle armour which provides protection for the crew, the vehicle's weapons, and its propulsion systems, and operational mobility, due to its use of tracks rather than wheels, which allows the tank to move over rugged terrain and adverse conditions such as mud, and be positioned on the battlefield in advantageous locations. These features enable the tank to perform well in a variety of intense combat situations, simultaneously both offensively with fire from their powerful tank gun, and defensively due to their near invulnerability to common firearms and good resistance to heavier weapons, all while maintaining the mobility needed to exploit changing tactical situations. Fully integrating tanks into modern military forces spawned a new era of combat, armoured warfare.