Law is a system of rules created by a government or a society to regulate behavior. It may be viewed as the foundation for justice, morality, reason, order, and civility.

The precise nature of law is a matter of debate. Some writers have asserted that law is a normative science, meaning it establishes standards and is enforceable through the sanction of the state. Others have argued that the law is simply a set of social customs and practices that vary between societies and eras.

Modern formal sources of law include statutes or legislation, judicial precedents, and case law. Judges are bound to apply these sources of law when deciding cases. Other informal sources are used as well, including foreign judgements, principles of morality or equity, and professional opinions.

There are two primary areas of law: criminal and civil. Criminal law deals with conduct that is deemed harmful to the social order and is punishable by imprisonment or fines. Civil law, on the other hand, resolves disputes between individuals or organizations.

The law shapes politics, economics, history and culture in many ways and raises a variety of complex issues concerning equality, fairness and justice. In addition, it is a major source of scholarly inquiry into legal philosophy, sociology, and history. For these reasons, it is important for all citizens to understand the nature and importance of the law. The five principal goals of the law are establishing standards, maintaining order, resolving disputes, and protecting liberties and rights.