Law is the body of rules that a particular community or state recognizes as binding on its members and enforces through a central authority. It shapes politics, economics and history in many ways and acts as a mediator of relations between people. It also imposes obligations on people, sets standards for behaviour and defines liberties and rights.
Laws can be derived from either written constitutions, statutes and regulations or from judge-made precedent, known as case law. The latter may be used as a basis for future legal decisions or as a guide to what courts will consider and accept in similar cases. This principle, known as stare decisis, is important in common law systems where judges write up their decision in full and bind later judges to the same ruling.
The major areas of law include contracts, property, criminal and commercial laws. Contract law covers all agreements relating to the exchange of goods or services and can range from buying a bus ticket to a complex contract for the sale of shares. Property law regulates people’s rights and duties toward tangible things like land or buildings, defining the distinction between real property (right in rem) and personal property (right in personam). Criminal and commercial laws apply to crimes such as murder and fraud, as well as business matters such as taxation and corporate governance.
Each area of law is further divided into sub-fields or branches. For example, family law deals with divorce proceedings and the rights of children. Commercial law encompasses banking and finance, insurance and bills of exchange. Land and planning law deal with ownership of land, zoning restrictions and the process of registering property. The development of these branches of law varies between different nation-states, with the nature of political power determining how and when laws are made and enforced.
The study of law is a complex and challenging field. It is unique among academic disciplines in that it has normative as well as descriptive elements. Normative statements in law imply what people ought to do or not do, but they lack the clear causal links found in empirical science (such as the law of gravity) or social science (such as the theory of justice). Law is also unusual in that its agents are highly specialized and have no means of checking the accuracy of authoritative statements. In order to practice law, an individual must achieve a distinct professional identity through specified legal procedures (e.g. passing a qualifying exam). This is typically overseen by an independent regulating body such as a bar association or bar council.