Law is a set of rules created by a society that are enforced by mechanisms that can punish those who break them. Those mechanisms can be civil or criminal. Law can also be a form of social control, or a way to insure fairness and equality. Law can be based on a religious text, a moral principle, or a scientific theory.

The precise nature of law is debated. Some philosophers, such as Jeremy Bentham, argue that it is “commands, backed by the threat of sanctions, from a sovereign whom people have a habit of obeying”. Others, such as Jean-Jacques Rousseau and Thomas Aquinas, believe that there are essentially moral laws that are universal and unchanging. Others, such as Oliver Wendell Holmes, describe law as “a betting system that predicts what men will do”.

Almost all nations have a legal tradition. Some of these traditions are similar, such as the English common law and Roman law. Other traditions are quite different, such as Hindu law and Islamic law. In general, a country’s laws reflect the culture and history of its people.

Some areas of law are specialised, such as banking and financial regulation, which sets minimum standards for banks to hold, or taxation law, which sets the rates of income taxes. Other areas of law are very broad, such as criminal or civil procedure, which covers the procedures that courts must follow as they decide cases. Laws may be made by a group legislature or individual legislator, resulting in statutes; by the executive through decrees and regulations; or by judges as precedents, which is common in some common law jurisdictions.