Law is a set of rules that are created and enforced by social or governmental institutions to regulate behavior. Its precise definition has been a matter of longstanding debate. Some scholars have described it as a science while others have referred to it as the art of justice. Law can be made by a legislature, resulting in statutes; by the executive, resulting in decrees and regulations; or by judges, resulting in precedent, often through case law. It can also be created by private individuals through contractual agreements and arbitration proceedings, which are alternatives to standard court litigation.

Some philosophers have attempted to define law using various approaches. The German philosopher Friedrich Nietzsche proposed that law is a force which serves to organize and control society. He suggested that the main purpose of laws is to fulfill social wants, and that people follow the law for a variety of reasons, including morality, religion, economic interests, and emotion. The American sociologist Roscoe Pound, in contrast, proposed that law is a tool of power, and that the primary function of law is coercive. He suggested that the social process of lawmaking is a struggle between competing pulls of political philosophy, economic interests and ethical values.

Legal theorist Hans Kelsen offered a purist theory of law, in which he defined law as a normative science which defines certain rules to follow. He considered it to be an empirical and observable science, and not a metaphysical truth. It is important to note, however, that even if a rule is objectively true, it may still not be followed. For example, a tyrannical government could pass laws that are so unpopular that the citizens ignore them, regardless of how objectively true they are.

The concept of law is closely linked to the concept of democracy. Democracies have laws that are designed to protect the rights of their citizens and to prevent the tyranny of dictatorships or other autocratic regimes. The basic principles of democracy are an independent judiciary; a transparent trial process that is accessible to all; equal rights and protections for all; and the right to freedom of speech and assembly.

A related term, often used in the context of law, is jurisprudence, which refers to the body of decisions by courts and other tribunals that are deemed to be authoritative on certain matters of the legal system. This discipline includes a wide range of topics, including constitutional law; criminal and civil procedure; evidence; torts; property law; and administrative and labor law. The study of jurisprudence is the central focus of many law schools, and is a vital part of the education of any lawyer. The practice of law is an essential component of a well-functioning society. It helps keep people safe, makes economies run smoothly, and allows for innovation and creativity in business. In addition, it provides a framework for addressing conflicts and disagreements. For these reasons, it is an important area for continued study and research.