The law is a set of rules enforced by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate, and it has been described as both a science and as an art.

From a societal viewpoint, the law defines standards of fairness and justice. It also reflects views on morality, order and honesty. The legal field can be divided into substantive and procedural laws. Substantive laws include codes, statutes and constitutions that establish the rights and responsibilities of individuals within society. Substantive laws can be further broken down into civil and criminal areas of law. Civil law deals with relationships between individuals, while criminal law concerns offences against the community as a whole.

Procedural law includes the procedures that must be followed by courts as they try cases. It also defines what materials are admissible as evidence in court cases. Generally, it is considered the most important branch of the law because it determines how substantive laws are applied in specific cases.

Laws impose restrictions on the conduct of citizens and are enforced by state and local authorities, or by self-governing bodies such as churches and businesses. They may deal with issues such as property ownership, employee rights and criminal activity. Regardless of their subject, laws are often complex and difficult to understand.

Although laws can be based on social or societal values, they are not a substitute for morality. For example, the prohibition against insider trading might reflect a moral position that all persons should be treated fairly. Similarly, the idea of due process might reflect a moral opposition to cruelty.

Some scholars believe that the concept of the law grew out of an ancient philosophy, or normative science, called naturalism. The theory of naturalism argues that all laws are derived from natural phenomena and are not created by humans. Other scholars, however, argue that the notion of law is a human construct and that the law reflects societal values, such as morality, order and justice.

The United States system of law comprises many levels of codified and uncodified law, including the nation’s Constitution, acts enacted by Congress, treaties ratified by the Senate, regulations issued by the executive branch and case law developed by the federal courts. The United States Code is a compilation of all federal statutory law, and is updated regularly.

The laws of a country are the foundation for the government that it establishes. Ideally, the law is fair and impartial and applies to all citizens, regardless of their wealth or status. It should also be clear and easily accessible. Finally, it should have checks on power to prevent abuses. In the United States, this is achieved through the separation of powers among the legislative, executive and judicial branches of the government. In countries that do not have this system, the law can become corrupt and authoritarian. In addition, the law should provide incentives to promote honest and ethical behaviour.