A main battle tank (MBT), also known as a battle tank or universal tank, is a tank that fills the heavy direct fire role of many modern armies. They replaced light, medium, heavy and super-heavy tanks. They were first majorly deployed during the Cold War.
Today, main battle tanks are considered a key component of modern armies. Modern MBTs seldom operate alone and are usually deployed in organised armoured units which involve the support of motorized infantry. They are often supported by surveillance or ground-attack aircraft.
The tanks defining characteristic is a large caliber gun mounted in a swiveling turret which serves as its primary armament. Secondary armaments come in the form of machine guns/auto-cannons mounted either coaxially with the main gun or on a swivel mount located on the top of the main turret. Some tanks have enhanced fire support capabilities in the form of Anti-Tank Guided Missiles which can reach targets outside the range of the main gun.
While tanks are very capable of taking on all land based vehicles, they have very limited anti-helicopter capabilities and no anti-plane capabilities. Sending an unsupported tank platoon against an enemy with competent air to ground resources is unadvisable.