Law is a system of rules that are created and enforced through social or governmental institutions to regulate behaviour. It can be imposed by a sovereign state, resulting in codified statutes and regulations, or by private individuals, resulting in contractual agreements or arbitration proceedings. The law shapes politics, economics, history and society in various ways. It is a mediator of relations between people, settling disputes and ensuring that the state adheres to its own constitution or principles.

The precise definition of law is a matter of longstanding debate. One of its most important characteristics is that it is a socially constructed concept, with its content not verifiable by empirical means, as it relies on the human mind to interpret and apply.

Modern law may be divided into two broad categories, civil and criminal. Civil law includes laws concerning contracts, property and commercial transactions; it also covers areas such as torts, negligence and consumer protection. Criminal law deals with crimes and the punishment of offenders. The latter category includes a wide range of offences, from traffic violations to murder.

There are many areas of specialisation within the legal profession, such as tax law, family law and employment law. The practice of law is overseen by an independent regulating body, usually the bar association or bar council, and requires a degree in law, usually a Bachelor of Laws (LLB).

Lawyers must pass a qualifying exam to be admitted as members of their country’s Bar. They are referred to as Esquire in some countries, and may have the honorific title of Lord, High Court Judge or Doctor of Laws.

Laws are a fundamental part of any state, and it is impossible to describe the nature of a state without reference to the laws that govern it. As a social construct, the law is constantly changing to reflect new ideas and trends, and its exact content is beyond empirical verification. However, it is generally agreed upon that laws must respect the rights of all individuals and ensure that the government abides by its own principles.

Historically, the most prominent source of law was religious scripture and doctrine. Religious law constituted the basis of Jewish Halakha, Islamic Sharia and Christian canon law, and to some extent is still prevalent in some churches. In addition to governing the spiritual life, religion has always played an important role in secular matters, influencing judges and governments through interpretation, Ijma, Qiyas, jurisprudence and precedent.