In modern parlance, artillery refers to an engine of war that uses stored energy, whether mechanical, chemical, or electromagnetic, to project munitions far beyond the effective range of personal weapons. The earliest forms of artillery were in large measure employed as stationary devices designed to breach fortifications or reduce a single obstacle. The destructive capabilities of early gunpowder siege weapons led to development of mobile versions suitable for employment on the battlefield. This development continues such that today artillery comprises highly mobile weapons of great flexibility in which repose most of a modern army's firepower.