military knowledge: what is Main battle tank ?

A main battle tank (MBT), also known as a battle tank or universal tank, is a tank that fills the armor-protected direct fire and maneuver role of many modern armies. Cold War-era development of more powerful engines, better suspension systems and lightweight composite armour allowed a tank to have the firepower of a super-heavy tank, armor protection of a heavy tank, and mobility of a light tank all in a package with the weight of a medium tank. Through the 1960s, the MBT replaced almost all other tanks, leaving only some specialist roles to be filled by lighter designs or other types of armoured fighting vehicles.

Today, main battle tanks are considered a key component of modern armies. Modern MBTs seldom operate alone, as they are organized into armoured units which involve the support of infantry, who may accompany the MBTs in infantry fighting vehicles. They are also often supported by surveillance or ground-attack aircraft.

History

During World War I, combining tracks, armor, and guns into a functional vehicle pushed the limits of mechanical technology. This limited the specific battlefield capabilities any one tank design could be expected fulfill beyond this. A design might have good speed, armour, or firepower, but not all three at the same time.

Facing the deadlock of trench warfare, the first tank designs focused on crossing wide trenches, requiring very long and large vehicles, such as the British Mark I tank; these became known as heavy tanks. Tanks that focused on other combat roles were smaller, like the French Renault FT; these were light tanks or tankettes. Many late-war and inter-war tank designs diverged from these according to new, though mostly untried, concepts for future tank roles and tactics. Each nation tended to create its own list of tank classes with different intended roles, such as "cavalry tanks", "breakthrough tanks", "fast tanks", and "assault tanks". The British maintained cruiser tanks that focused on speed, and infantry tanks that traded speed for more armour.