Firepower is the military capability to direct force at an enemy. (It is not to be confused with the concept of rate of fire, which describes cycling of the firing mechanism in a weapon system.) Firepower involves the whole range of potential weapons. The concept is generally taught as one of the three key principles of modern warfare wherein the enemy forces are destroyed or have their will to fight negated by sufficient and preferably overwhelming use of force as a result of combat operations.
Artillery is a class of large military weapons built to fire munitions far beyond the range and power of infantry’s small arms. Early artillery development focused on the ability to breach fortifications, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility providing the largest share of an army’s total firepower.