Law is a set of rules that are created and enforced by social or governmental institutions to regulate behavior. It has been described as a science and as an art of justice. Law serves four principal purposes: it establishes standards, maintains order, resolves disputes and protects liberties and rights. In its broadest sense, the term law may also refer to specific legislation or to more broadly defined provisions of constitutional or international law.

In the United States, laws may be enacted by Congress, state legislatures or local governments. Governments may also pass regulations that govern business, health care and other areas of life. For example, laws might dictate how survivors of domestic violence are treated or how much funding is available for research into that type of abuse. The term law can also refer to a profession, such as the legal profession.

The United States Constitution assigns Congress the task of organizing the executive and judicial branches of the federal government, raising revenue, declaring war and making all laws necessary for executing those powers. The president is allowed to veto specific legislative acts, but Congress can override presidential vetoes by two-thirds majorities in both the House and Senate. The Constitution also requires that the Senate advise and consent on key executive and judicial appointments and on ratification of treaties.

Legal laws can apply to a wide range of topics, including contract law, property law and criminal law. Contract law is the set of rules that regulate agreements to exchange goods or services for money, and it includes everything from buying a bus ticket to trading options on a derivatives market. Property law defines people’s rights and duties toward tangible property, such as land or buildings, and intangible property, such as bank accounts and shares of stock. Criminal law sets the punishments for certain crimes and the rights that criminals have, while civil law determines the rights and responsibilities of those who are not criminals.

While the precise definition of law is a subject of longstanding debate, many different types of laws exist. A scientific law is an indisputable fact based on empirical evidence, such as Newton’s Law of Gravity or Mendel’s Law of Independent Assortment, according to the University of California, Berkeley. A scientific theory, on the other hand, is an explanation of why a phenomenon occurs but cannot be proved with absolute certainty.

For more information about laws and the legal system, see the articles on the legal profession, law school and legal ethics. For more information about the role of law in a democracy, see law and democracy. For more about restrictions on society, see censorship; crime and punishment; and military law. The article on law is part of the Law and Society Encyclopedia. It is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.