In World War Two blitzkrieg, the German for 'lightning war', became one of the main ways of fighting. In World War One masses of infantry (foot soldiers) had kept on attacking lines of trenches and thousands of men were lost- dead and wounded. The tank was seen as the way to attack the enemy's trenches without such huge casualties. It was a vehicle, which could crush barbed wire and slowly rumble over the trenches. Its armour, made of steel plate, protected it from rifle and machine-gun fire. It could make a gap in the enemy trench line for the infantry to break through. This was how the British and French armies expected to fight World War Two-with infantry supported by slow-moving tanks ('Infantry' or '1' tanks).

The German army was a step ahead. Blitzkrieg was a different idea altogether. This was fast moving warfare, which made use of both the tank and aircraft. Its essence was speed and surprise. The air force would attack first, bombing enemy defences. Then the main force would move in large numbers of tanks travelling at speeds of up to 30,40 km per hour, with infantry following in motor trucks ('motorised infantry'). The main tank force would smash through the weak spots in the enemy's defences, avoiding strongpoints and would quickly sweep forward as far and as fast as possible. Motorcyclists with machine-guns in sidecars would fan out to front and sides looking for signs of enemy counter-attacks. Later in the war, armoured cars would do this. Throughout the attack the air force would support the ground forces, dive-bombing enemy strongpoints so that the tanks and infantry could move in. The dive-bombers used are usually the Stuka.

Many in the High Command of the German Army before the war had little interest in the idea of blitzkrieg. But Heinz Guderian, with Hitler's support, created the deadly 'panzer' (armoured) divisions, which proved so successful during the early stages of the war.

The British and French did not adopt blitzkrieg immediately, and the Germans did well at first because they used the new ideas and their enemies did not. This changed as the war went on. Both sides came to see the value of anti-tank guns and rockets. The tanks had to rely on infantry carried in armoured halftracked vehicles, to attack and destroy these dangerous anti-tank weapons. Tanks, infantry and artillery (guns) worked together in teams, each depending on the others.

In battle, tanks made use of folds in the ground. In the 'turret-down' position only the tank commander could see over the ridge. Advancing to the 'hull-down' position the tank gun could fire while the ridge hid the rest of the tank. The low-velocity gun, usually of 37 to 55 mm calibre, fired its shot in a curved path. The high velocity gun, of 50 to 75 mm calibre or bigger, could aim directly at the target without having to find its range.