Law is the study of the system of rules that a country or community recognizes as regulating its citizens’ actions. The rules are enforced by a controlling authority through penalties. The most common types of laws are legislative statutes, duly enacted by a national or local government and regulations, the final product of a regulatory agency’s considerations. A third type of law is judicial decisions, the rulings of a judge or group of judges in a case which are then given broader legal weight to apply in future cases (the principle of “precedent” or “stare decisis”).

The study of law is very broad and can include such topics as contracts, criminal, constitutional, property and family law. Contract law, for example, involves the agreements people make to exchange goods and services. Constitutional law focuses on areas of government that are expressly reserved to the federal government in the U.S., such as the military, money, foreign affairs, tariffs and intellectual property. Property law is the study of people’s rights and duties toward their tangible property, such as land and buildings, as well as their intangible property, such as bank accounts and shares of stock.

While many legal scholars believe in the “legal positivism” that says that laws must be interpreted and applied objectively, some think that law has other purposes. For example, some laws seem to imply a moral stance, such as the prohibition against insider trading or due process.