Law is a set of rules that are created and enforced by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate. Some describe it as a science and others as the art of justice. Law shapes politics, economics, history and society in many ways. Some of its most significant impacts are that it sets standards, maintains order, resolves disputes and protects liberties and rights. The law may be enacted through legislative statutes or executive regulations, judicial decisions or by custom and convention. The department of knowledge devoted to studying such rules is called jurisprudence.

The fundamental purpose of laws is to serve the needs of a nation by providing stable and predictable social conditions that enable prosperity and well-being. The nature of these needs varies from one country to another. Some nations, such as the United States and France, have written constitutions that include a bill of rights that defines the fundamental freedoms of citizens. Others, such as China and India, have traditions of law based on scriptures and customary practice.

While the primary functions of law vary from nation to nation, most legal systems share four principal aspects. The first of these is the establishment of standards. This includes legal provisions describing what is considered reasonable in specific situations, such as deciding what is fair or unfair treatment under the workplace law. It also encompasses enshrining principles for how people should be treated, such as the law of negligence or the law of contract.

Maintaining order is the second function of law. It is achieved through rules and regulations governing everything from traffic regulations to prison sentences. It also covers the preservation of social stability by preventing uncontrolled or chaotic change, such as in times of war. It also imposes limits on the growth of government to ensure that it remains democratic and accountable.

Resolving disputes is the third of the law’s fundamental functions. It is achieved through establishing and upholding enforceable rights, as well as settling arguments over property, money and status. Some of these disputes are very complex, and the judicial system has to draw on its experience to create workable solutions. For example, in the 1948 case Associated Provincial Picture Houses Ltd v Wednesbury Corporation [1948] 1KB 223 (CA), the court had to establish what was’reasonable’ to allow filming of public events in commercial cinemas.

Protecting liberties and rights is the fourth of the law’s fundamental functions. This encompasses both the rights of individuals against the state and the protection of private property by national and international laws. It also involves ensuring that the people of a nation know who makes and enforces their laws, and that they can freely express their wishes in elections and referenda.

The creation and application of law is a complex process that varies greatly from one nation to the next. A key challenge is that in most modern polities, the political power to make and enforce law rests with people who do not always exercise this democratic control voluntarily. Consequently, revolts against existing political-legal authority are commonplace in countries around the world.