Law is the system of rules created and enforced through social or governmental institutions to regulate behavior. Its precise definition remains a subject of longstanding debate, but it is commonly described as both a science and an art.
There are many kinds of law, which can be broadly classified as administrative, constitutional, criminal, contract, evidence, property, and tort law. Within each of these broad categories are many more specific areas of law, for example consumer, aviation, bankruptcy, maritime, medical jurisprudence, and competition law.
The sources of law are varied: they may be legislative—in the form of statutes or constitutional codes and in the form of legal precedent, known as stare decisis; or regulatory—in the form of government decrees or regulations, or private—in the form of private contracts and arbitration agreements. The most common sources of law today are statutory and case law, although some jurisdictions have codified their constitutions and use traditional judicial decisions for their legal authority, and others have legislative or executive bodies that produce and enforce laws.
Religious law also provides a source of law, particularly Jewish halakha and Islamic Shari’a, but even this is dependent on human elaboration through interpretation (qiyas and ijma), codification, precedent, and stipulations based on a given religion’s scriptures and teachings. The precise nature of law makes it unique from other disciplines, with its own set of logical problems and issues. See also constitutional law; international law; and legal theory. For an overview of the processes involved in creating and enforcing law, see legal system.