Law, in the broadest sense, is a set of rules created and enforced through social or governmental institutions to regulate behavior. Law has multiple functions, including establishing standards, maintaining order, resolving disputes and protecting liberties. It is a complex field, with its precise definition a matter of debate.

A legal system can be established by a central body through statutes or decrees, or through judicial decisions, in common law jurisdictions. Religious law, particularly Jewish halakha and Islamic Sharia, remains a significant component of the legal system in some communities. Private individuals may create legally binding contracts and agreements, as well as create binding arbitration agreements to settle disputes.

The study of laws and the system of courts that interprets them is known as jurisprudence. A lawyer is a person who practices law, advising clients on legal issues or representing them in court. A judge is a person who presides over trials, deciding the outcomes of lawsuits and other disputes. A clerk is an individual who assists judges with research and drafting opinions.

Many different kinds of laws exist, covering many different areas of human activity. For example, property laws encompass real and personal property, as well as a system of land registration and ownership. Other types of law include commercial, intellectual and company law. Criminal laws, which deal with punishment for crimes committed, and civil rights laws are also important parts of the legal system.

People who follow the law are called lawyers and judges, and a career in law is regarded as an honourable profession. Lawyers are trained to analyse, explain and defend the law, with the ability to think rationally and communicate well. They are able to take a stand on controversial changes in legislation, and they have a responsibility to their clients to advise them of the risks involved in particular courses of action.

In some cases, a law may be a moral imperative, such as the laws against murder and rape. In such situations, the law is not simply a set of regulations; it is an idea that guides society and shapes the lives of its citizens. There are few living cultures that rely on a non-modern concept of the law, but some, such as the Inuit people, have a concept that does not dichotomize reality into natural and human/humane.