Law is a set of rules created and enforced by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate, and it has been variously described as a science and as the art of justice. Law shapes politics, economics, history and society in many ways, and serves as a mediator of relations between people.

The study of law encompasses a wide range of topics, from legal system design to the development of individual laws. A general distinction can be made between civil law jurisdictions, in which a central body codifies and consolidates their laws, and common law systems, in which judge-made precedent is binding. In addition to codified laws, other sources of law include constitutional law and natural law, as well as edicts from religious authorities.

Legal systems vary widely from one country to another, with the United States employing a common law system that relies on judicial decisions compiled into a body of case law; this contrasts with civil law systems such as those used by Japan and Germany, which base their laws on a code enacted by a central body. Other sources of law include constitutional law, which sets forth the fundamental rights and responsibilities of citizens; family law, which governs the relationship between parents and children; labour law, which deals with the tripartite industrial relation between employer, employee and trade union; criminal law, which defines what is considered to be a crime; and property law, which establishes the right to own and use property.

The principal functions of law are to keep the peace, maintain the status quo and protect individuals against oppressive majorities or minorities. However, the extent to which a nation’s law fulfils these roles is determined by its political structure. A democracy will promote social change and provide greater rights for citizens, while an authoritarian regime may suppress dissent and control the economy. In addition, the power to make and enforce law varies greatly from place to place.

Oxford Reference provides more than 34,000 concise definitions and in-depth, specialist encyclopedic entries on every aspect of law. Our comprehensive coverage includes criminal, civil and common law; international law; family and labour law; intellectual property law; and major debates in legal theory. It also covers a broad spectrum of terms and concepts, from the meaning of arraignment to evidence law and the role of public defenders in criminal cases. Our trusted, authoritative content is designed for researchers at all levels.