Law is a set of rules that a society or government develops to deal with things like crime, business agreements and social relationships. These laws are enforced by a controlling authority, usually through penalties like fines and jail time. The word is also used to describe the legal profession that applies the law to individuals, businesses and organizations.

Law varies widely from one country to the next, and the differences are largely tied to political circumstances and history. For example, many countries have a constitution that establishes the limits of their national sovereignty and gives power to their governing bodies. Others, like France and the United States, have constitutional bills of rights that protect the civil liberties of their citizens against abuses by the executive, legislative and judicial branches of government.

In the United States, the federal government enacts statutes and regulations to enforce the Constitution. A large percentage of federal law is based on the broad interpretations of the powers granted to Congress in the Commerce and Spending Clauses of the Constitution, and it covers areas like aviation, telecommunications, railroads, foreign relations, taxes, intellectual property (specifically patents and copyrights), mail, and insurance. But in other fields, such as family law, a small number of federal statutes interact with a much larger body of state law.

Most societies, especially industrialized ones, have a legal system that defines and defends the rights of their citizens to free speech, privacy, equal treatment under the law, and freedom from unreasonable search and seizure. In some countries, a majority of the people elect their representatives to create and interpret the law. But in other nations, the power to make and enforce the law is concentrated in the hands of the ruling elites. Revolutions against these centralized, autocratic regimes are commonplace.

A wide variety of fields and scholarly disciplines study the law. For a more general overview, see legal studies; legal ethics; and legal education. For articles on specific topics, see contract; constitutional law; criminal law; property law; and torts.

A legal researcher can find useful resources on the Internet through an abstracting e-Journal, the Victoria University of Wellington Legal Research Papers, or SSRN. A subscription is required to access full text papers. The site is also a great place to look for articles on the philosophy of law. For other articles on the relationship between law and social justice, see law and human rights; political democracy; and law and the military. For other articles on the political structure of a country, see constitution; ideology; political party; and political system.