Law is the set of rules that social or governmental institutions create and enforce to regulate behavior. Its precise definition is the subject of long-running debate. Law is generally viewed as the basis of social order and justice. It is also seen as a normative science that lays down standards to be obeyed.

For example, it is a legal standard that adults must not commit adultery in public. The term may refer to a single act or statute, the body of laws in a country, or the legal system in general. It is an important concept in international relations and human rights, as it refers to the principle of governance under which individuals, organisations and businesses are accountable to publicly promulgated, equally enforced and independently adjudicated laws. It is a requirement of the United Nations that the state comply with this normative science and the principles of supremacy of the law, equality before the law, separation of powers, participation in decision-making, and legal certainty and transparency.

Some theories of law define it as the ‘legal process’; others focus on the specifics of individual laws. The sociological school focuses on the interaction between law and society, while the philosophical school aims to provide a more abstract view of law.

There are many branches of law, including contracts (which govern agreements to exchange goods or services), property (which determines rights and duties toward tangible objects, such as land or buildings), and intellectual property (such as patents). The various areas of law are studied by a variety of people, from lawyers to sociologists to economists.