The infantry tank was a tank concept developed by the United Kingdom and France in the years leading up to World War II. Infantry tanks were designed to support infantrymen in an attack. To achieve this, the vehicles were generally heavily armoured to allow them to operate in close concert with infantry even under heavy fire. The extra armour came at the expense of speed, which was not an issue when supporting relatively slow-moving foot soldiers.

Tank classification is a taxonomy of identifying either the intended role or weight class of tanks. The classification by role was used primarily during the developmental stage of the national armoured forces, and referred to the doctrinal and force structure utility of the tanks based on design emphasis. The weight classification is used in the same way truck classification is used, and is intended to accommodate logistic requirements of the tanks.