Law is the system of rules that a society or government establishes and enforces to regulate behavior. It is generally understood as a set of restrictions that are enforceable through penalties. The precise definition of law is the subject of long-running debate, with various scholars offering competing theories. A utilitarian approach, exemplified by John Austin, defines law as “commands, backed by threat of sanctions, from a sovereign, to which people have a habit of obedience.” Other theorists, such as Jean-Jacques Rousseau, have argued that law reflects essentially moral and unchangeable laws of nature.
Different countries have different legal systems. For example, the United States has a common law system where laws are derived from judicial decisions and compiled into case law. In contrast, other nations have civil law systems where laws are based on written codes.
The study of law encompasses a broad range of subjects including criminal, civil, contract, family, property, maritime, and administrative law. It also covers areas of specific practice such as arraignment, discovery, and trial procedure.
The study of law has a strong relationship to politics and the political system. For more on this see article on democracy and the law; constitutional law; constitutionalism; government structure; and political parties. It also has a direct relationship to social issues such as justice and equality before the law. For more on this see article on social rights and equality; censorship; and crime and punishment. In addition, laws are the foundation for economic and social policies.