Law shapes politics, economics, history and society. It also serves as a mediator of relations between people.
Legal systems differ widely across the world. Some systems are based on principles and concepts derived from Roman law, while others are primarily influenced by local custom or culture.
A national legal system regulates the actions of its citizens and the institutions that govern them. It is used to keep the peace, maintain the status quo, protect individual rights, promote social justice, and provide for orderly social change.
In some systems, laws are made by a group legislature, resulting in statutes; by the executive, through decrees and regulations; or established by judges through precedent, usually in common law jurisdictions.
The precise definition of law is a matter of long-standing debate. It has been variously described as a science and as the art of justice.
Legal systems are divided into common law and civil law. In the former, decisions of courts are explicitly acknowledged as “law” on equal footing with statutes adopted through the legislative process and with regulations issued by the executive.
Examples of common law systems include the United States, the European Union, and many Australian provinces. In these jurisdictions, decisions by higher courts bind lower courts and future decisions of the same court to ensure that similar cases reach similar results.
The practice of law is typically overseen by a government or independent regulating body such as a bar association, bar council or law society. Lawyers achieve a distinct professional identity through specified legal procedures (e.g. successful examination), are required by law to have a special qualification and are constituted in office by legal forms of appointment (being admitted to the bar).