Law is the system of rules that are created and enforced through social or governmental institutions to regulate behavior. Its precise definition is a matter of ongoing debate, but it can be roughly described as an area of knowledge that deals with the relationships between individuals and between individuals and their environments. It may be written or unwritten, and can be formal or informal, or both. It can cover many different subjects, including human rights, labour law, criminal law and competition law.
Law can also be a set of principles based on observable natural processes or on the predictability of events under certain conditions: for example, the law of gravity. Moreover, it can be used to describe the properties of an object or a phenomenon: for instance, the law of thermodynamics. Finally, it can be a statement about an aspect of a particular activity: for example the laws governing the playwriting craft.
A large part of the field of law is concerned with the ways in which rules are created and enforced: the drafting and amending of legislation; the administration of justice, especially trial by jury, or by judges on appeal; and the training of lawyers and jurists. Another major part of the subject focuses on specific topics of the law, such as property law, family law and criminal law.
Legal systems vary from one country to another, but some common features include:
The system of law can be established by legislative process, resulting in statutes; by executive decree and regulation, usually under the heading of administrative law; or through judicial decisions, especially in “common law” countries. The latter, called the doctrine of stare decisis, states that a previous court decision binds subsequent courts, so that similar cases are likely to reach similar results.
Law is also the basis of a variety of other disciplines, such as anthropology; economics; philosophy; politics and religion. For more on these fields, see the articles for them. Several areas of law are governed by specific religious precepts: for example, Jewish Halakha and Islamic Sharia, and Christian canon law.