Tankes were mainly invented to help war fare and they had many advantages because they could carry men and sheld them while the main gun returned fire on the enemy.Another thing is there ability to fire eye to eye and then they could also fire at an angle to arch down.They had a large impact on ww1 and all of the wars to come for they could shoot exploding rounds.The fastest tank is the Mark one whippet which could go up to 30mph that's really fast for a thank.The British firt used the tanks and called them land ships.