The law shapes politics, economics, history and society in many ways and functions as a mediator of relations between people. It includes the rules, regulations and policies that determine how people should interact with one another, whether in a business transaction or an accident on a road. Almost all societies have some kind of legal system that defines and regulates these interactions. The field of law also encompasses the professions that give advice about law, defend or punish people who break the rules and those who enforce them.
Law is also the body of rules that governs the actions of a government and its citizens. It includes statutes, executive orders and judicial decisions. Governments make laws to control their people and resources, and they enforce laws through military and police forces. These powers have their limits, as reflected in the ongoing struggle over democratic rule and increased citizen rights around the world.
Legal systems vary across the world, and they reflect the cultural values of the nation-states that create them. In some countries, judges and lawyers may have a professional code of ethics that guides their behavior. The concept of law has been shaped by a range of philosophical ideas. Utilitarian philosopher John Austin argued that law reflects commands, backed by the threat of sanctions, from an authority to whom people have a habit of obedience. Jean-Jacques Rousseau and others promoted the idea of natural law that reflects underlying moral principles of human nature.