Heavy tank
The Char 2C was one of the largest tanks ever produced. At the start of World War II, France and the Soviet Union were the only countries to have inventories of heavy tanks, such as the Char B1, T-35, and KV-1. The Matilda II was designed under the British infantry tank concept which is similar to the heavy tank having thick armor and weighing more than their other tanks. It’s usually separate because they have less firepower with their cruiser tanks (comparable to mediums) at the time having the same main armament but more machine guns. Later war examples were the German Tiger I and II, as well as the Soviet IS series. Note that "heavy" versus "medium" is more a question of tactical roles than weight; the Panther, for example, was a "medium" tank that outweighed most Allied "heavy" tanks.
Tanks of the interwar period
Later German tanks received a new designation, "Panzerkampfwagen" (PzKpfw or PzKw), which means "Armoured Fighting Vehicle". The first machine to use this was the two-man PzKpfw I Ausf A influenced by the Carden Loyd tankette, and was a 5.4 ton machine with a 3.5-litre 60 hp (45 kW) petrol engine. It had 13 mm of armour and was armed with twin 7.92 mm machine guns. The more common Ausf B was a little larger to accommodate a 100 hp (75 kW) Maybach engine. Both models were sent to the Spanish Civil War for testing, along with other new German weapons. From the experiences in Spain it quickly became clear that the next generation of tanks would need better armour, greater range and much heavier weapons.
The PzKpfw II was around 50% heavier than the PzKpfw I. It had a 20 mm Solothurn antitank gun as main armament, as well as improved armour of up to 30 mm. Also sent to Spain from 1937, the PzKpfw II proved more capable against light infantry, but no better when faced with capable anti-tank guns or other tanks. Despite these weaknesses, production continued until 1941. At the outbreak of war, the German Army had 955 PzKpfw IIs and almost 4000 were built in total.