Law is a system of rules enforced by society or the state that governs the behavior of individuals and groups. The precise definition of law is a subject of ongoing debate, but it usually involves an authoritative source stating what must happen, and a process by which that is enforced. The main functions of law are establishing standards, maintaining order, resolving disputes and protecting liberties and rights.
Legal systems vary from country to country. Government-enforced laws may be made by a legislative process, resulting in statutes; decreed by the executive through regulations and orders; or by judges through precedent, a concept known as “stare decisis”. Private individuals may also create legally binding contracts enforceable by courts, such as arbitration agreements, and may dispute the results of court litigation by taking their case to a different tribunal. Tort law covers compensation for damages caused by automobile accidents or defamation, while criminal law deals with offenses against the nation-state or community itself.
The practice of law also includes the specialised fields of immigration law and nationality law, which deal with the rights of foreigners to live and work in the territory of a nation-state, to acquire or lose citizenship and to move between nations. Family law covers marriage and divorce proceedings and the rights of children, while commercial or transactional law concerns business and money. Other areas of law include space law and biolaw, which concern the intersection of law with life sciences.