Law is a set of rules that are enforced through social or governmental institutions to regulate behavior and ensure that individuals adhere to a code of conduct. The precise nature of law is the subject of a wide range of scholarly inquiry, including legal history, philosophy, economic analysis and sociology. The law shapes politics, economics and history in various ways and serves as a mediator of relations between people.

A fundamental goal of law is to promote a peaceful society, and one of the primary ways it does this is by guaranteeing that all members of society are treated equally. Even in a well-ordered society, conflicts will arise. The law provides a process for resolving those disputes without fighting, for example by determining who owns a piece of property. It also protects the rights of private citizens against infringements by the government or other public officials.

The laws of a society are created by the collective effort of its legislative and executive branches, resulting in statutes and decrees, or through judge-made precedent in common law jurisdictions. The laws of a community may be religious in nature, such as the Jewish Halakha and Islamic Sharia, or they can be based on secular precepts.

Among the more specific fields of law are criminal law, which deals with offenses against the state, such as murder and treason, and civil law, which addresses disputes between private individuals. Other fields of law include family law, which outlines the rights and obligations of married and unmarried couples, and property law, which defines ownership and transfer of property.

Laws of business and commerce are governed by commercial law, which encompasses complex contract and property principles. Insurance law, bankruptcy law and the law of agency are also part of this field. Banking law establishes the minimum amount of capital that a bank must hold, and rules about financial investment are set by banking regulation. Tax law is a critical component of the economy, with regulations concerning value-added tax, corporate tax and income tax.

The law of space, meanwhile, covers the rights and duties of people who operate satellites, or travel to other planets. It also addresses the rights of aliens, who are recognized by the law as having some degree of autonomy.

The law of a nation-state includes treaties, immigration and nationality laws, which deal with the rights and obligations of foreign citizens and non-citizens within that country, and the laws of asylum and statelessness. It also covers the laws of international conflict and war, such as laws governing the use of force against another nation, and the laws of military conscription and incarceration. In addition, it includes the law of the sea, which applies to vessels that sail across international waters. It is an area of law that is constantly evolving, as evidenced by the recent U.S. anti-trust laws against price fixing by large corporations. It is an important source of inspiration for academic research and the development of new forms of law.