Law is a set of rules that are created and enforced by social or governmental institutions to regulate behavior. It has been variously described as a science and as the art of justice.
Legal systems vary from region to region, depending on the sources recognized as authoritative by a particular jurisdiction. Common sources include legislation, codifications in constitutions or statutes, and custom.
The laws of a country are often divided into civil law and common law. The former is based on concepts, categories and rules derived from Roman law, with some influence of canon law and sometimes supplemented by local customs or culture.
Civil law is characterized by a system of standardized codes that define the cases that can be brought to court, how claims are handled and the punishment for an offense. Standardized codes can be helpful in reducing bias and simplifying judicial procedures.
Competition law is a field of law that deals with monopolies, price fixing and other forms of unfair competition in business. Its roots trace back to the Roman decrees against price fixing and the English restraint of trade doctrine.
Regulation is another field of law that sets minimum standards for businesses and imposes controls on them to avoid excessive profits or damage to society. Those rules can range from minimum capital requirements for banks to restrictions on the use of energy, gas or water.
In most countries, law is made by a government. If a citizen breaks the law, they can be fined or put in jail.