Law is the set of rules created and enforced through social or governmental institutions to regulate behavior. Its precise definition is a topic of ongoing debate. Laws can be enacted by a collective legislature, resulting in statutes, by the executive through decrees and regulations or by judges, resulting in case law. They can also be privately made, resulting in contracts. Laws can be derived from morality or religion or by natural science.

Laws cover a wide range of subjects. The most fundamental laws are the ones governing physics and biology, such as the laws of gravity or the laws of thermodynamics. In contrast, other laws are more specific to particular disciplines or fields of interest. For example, patent law focuses on intellectual property rights such as trademarks and copyrights, while tax law relates to the laws and policies of the federal and state governments that govern how businesses are taxed.

In general, laws serve the purpose of establishing standards, maintaining order and resolving disputes between people. They can also serve the purposes of preserving individuals’ freedoms and rights, protecting minorities against majorities and facilitating social change. Different legal systems may be better at achieving these goals than others.

An individual’s decision to follow or not follow the law is a rational choice. The laws that guide the decisions of a society, such as criminal or civil law, are based on this concept.

A society’s laws can be based on the beliefs and traditions of its people, whereas other societies base their laws on a scientific or philosophical system. A society’s laws can also be based on its values, such as honesty and fairness.

Legal systems can be broadly categorized as civil, common or Islamic. The civil law tradition is found on most continents and covers about 60% of the world’s population. This system is based on concepts and categories developed in Roman law, with some influence from canon law, and sometimes augmented by local custom and culture. Common law, on the other hand, is based on precedent and an adversarial judicial process.

The laws that a society establishes may have the effect of shaping its politics, economics and history. Other articles in this section examine these aspects of law in more detail. These include constitutional law; ethics; the legal profession; and legal education. Other articles examine particular topics within the field of law, such as family law; labour law; and tort law. Still other articles discuss the relationship between law and the political system, including the effects of a government’s constitution on its laws. Still other articles analyze the role of law in specific social issues, such as the right to a fair trial and the law of war.