Law is a set of norms, rules, and codes that govern a society and the conduct of individuals. It has been described variously as a science and an art of justice. Its creation and enforcement are carried out by governmental or social institutions. In a common law country, laws are made by a group of legislators, a single legislator, the executive through decrees, or by judges. Private individuals can also create legal documents, such as contracts and arbitration agreements.

In the United States, competition law is known as antitrust law, and traces its roots to the restraint of trade doctrine and Roman decrees against price fixing. Today, antitrust law controls businesses that distort market prices. Other branches of law include banking, which controls bank accounts and sets minimum capital requirements. It also regulates investments and financial transactions.

In medieval Europe, legality and the rule of law were debated by the philosopher Aristotle and political theorist Niccolo Machiavelli. These debates continued through the early modern period and into the modern era. However, there were some differences between their views. Some thinkers viewed the Rule of Law more closely than others.

While traditional rule of law models sought to create a framework for the allocation of power, modern legislation is characterized by complex communication methods. By contrast, traditional Rule of Law models envisaged simpler means of communicating with the public.