Law is a complex field that shapes politics, economics and history in many ways. Its main function is to mediate relationships between people, so that conflicts may be settled and justice served.
Most modern legal systems involve a legislature that codifies and consolidates laws, or a judiciary that interprets and enforces them. The main branches of law are criminal, civil and administrative.
In some countries that do not have strong formal systems of law, customary law may survive. These are usually based on long-standing local traditions that greatly shape ideas of justice. They are not as well-defined as the laws of a country, so that disputes are decided case by case, without the use of a formal trial.
Other important areas of law include labour and employment law, immigration and nationality law and family law. These deal with the rights of workers and citizens in their relationship to each other and the nation-state, and the rights of families to each other, their property and money.
The word law, also called jurisprudence, refers to the body of rules and practices that govern a society. It is contrasted with a constitution, which is the written text of the fundamental principles and rules of a society. A person who studies or practises law is called a lawyer. Lawyers may be referred to as solicitors or barristers, depending on the jurisdiction in which they practice. Some lawyers are titled Esquire or Doctor of Law to signify their professional status.