Law is a system of rules created and enforced by social or governmental institutions to regulate behavior. It may include the principles of right and wrong, fairness, and justice, with penalties for violating them. Laws can be made by a group legislature, resulting in statutes; by the executive through decrees and regulations; or by judges in common law jurisdictions, whose decisions are recognized as law (under the doctrine of stare decisis). Individuals may also create legally binding laws, such as arbitration agreements that provide alternative ways of resolving disputes to standard court litigation.

Different authors have provided various definitions of Law. Roscoe Pound defines it as a mechanism for controlling human wants and actions and keeping societal order. Hans Kelsen, on the other hand, proposed a “pure theory of law,” which considers it to be nothing more than a set of rules that must be obeyed because they are necessary for human existence.

There are a variety of purposes that can be served by Law, with the most important being to establish standards, maintain order, resolve disputes, and protect rights and liberties. However, not all legal systems serve these purposes well. For example, an authoritarian regime might keep the peace and preserve the status quo, but it might oppress minorities or opposing political opponents. A democratic regime, on the other hand, might ensure civil rights and promote social change through the legal system. See the article on the Legal System for more information.