Law is the system of rules that a society or government develops to govern its citizens, businesses and relationships. It is often enforced by the state with penalties for transgressions. It serves four purposes: setting standards, maintaining order, resolving disputes and protecting liberties and rights.

The term can also be used to refer to the profession of lawyer or jurist, which includes legal assistants and paralegals as well as attorneys and judges. The word is also sometimes used to refer to specific legal areas, such as family law, criminal law or corporate law.

Different countries have different law systems, with some relying on judicial decisions instead of legislative statutes. A common law system, for example, places judicial decisions on an equal footing with legal statutes and regulations; this is called the “doctrine of precedent” or stare decisis. In contrast, civil law systems typically place judicial decisions lower down in the hierarchy than legal statutes, so that future adjudicators must follow those previous decisions.

Contract law defines people’s rights and duties in exchange for goods and services, such as contracts to purchase houses or cars. Property law defines a person’s rights and duties toward tangible property, including land and buildings, as well as intangible property such as shares of stock. Tax law defines the rules that govern a nation’s taxation system, including both income and corporate taxes. Banking and financial regulation imposes minimum capital requirements for banks as well as rules about best practice for investment. Public service and utility laws impose varying degrees of social responsibility on companies who manage or provide services such as electricity, gas, water and transportation.

Disputes between individuals, such as those involving a car accident or defamation, are the subject of civil law, which provides for compensation. Offenses against a national or local community are the subject of criminal law, which can include terrorism or drug trafficking.

The rule of law is the principle that all members of a given society are considered to be equal under publicly disclosed, transparent legal codes and processes. This protects against anarchy or the Hobbesian war of all against all, and also provides a degree of predictability that allows citizens to plan their activities with some confidence in knowing what the legal consequences will be. The concept of rule of law is a core element of modern constitutional democracy, with its underlying values and goals reflected in the precepts of human rights and freedoms. It is also a central component of religions’ codes and traditions, such as the Jewish Halakha or Islamic Sharia.