Military tactics encompasses the art of organising and employing fighting forces on or near the battlefield. They involve the application of four battlefield functions which are closely related – kinetic or firepower, mobility, protection or security, and shock action. Tactics are a separate function from command and control and logistics. In contemporary military science, tactics are the lowest of three levels of warfighting, the higher levels being the strategic and operational levels. Throughout history, there has been a shifting balance between the four tactical functions, generally based on the application of military technology, which has led to one or more of the tactical functions being dominant for a period of time, usually accompanied by the dominance of an associated fighting arm deployed on the battlefield, such as infantry, artillery, cavalry or tanks.