Law is the system of rules a state establishes and enforces to govern its citizens. It is often based on a constitution, written or tacit, and the rights encoded therein. The law shapes politics, economics, history and society in many ways and functions as a mediator between people. It is an area of study encompassing various disciplines and approaches, such as jurisprudence, sociology of law, and philosophy of law.

Laws can be broken by violating them, which may result in sanctions such as fines or imprisonment, depending on the violation and the laws that are breached. Generally, laws are created by the state to keep its citizenry safe and to promote peace. Laws can be broken by actions such as murder or fraud.

Historically, the study of law has relied primarily on logic and reason. However, other tools are required for a fuller picture of how the law works. The felt necessities of the time, the prevalent moral and political theories, intuitions of public policy, avowed or unconscious, even the prejudices of judges, have all had a great deal to do with the shape of law.

The law is a complex field with a broad range of topics and issues. Some of these include constitutional law, international law, family law, labour law, environmental protection and aviation law. There are also many different approaches to the study of the law, some of which are more academic in nature and others that are rooted in practical applications.

Legal issues are a constant feature of modern life. For example, there is much debate over whether judges should be allowed to use their own personal values when interpreting the law. Other hotly contested areas include the need for more diversity in the legal profession and the extent to which judges should be allowed to ignore the law when it conflicts with their own ethical values.

A major function of the law is to determine who has power and authority in a nation. It is also a source of conflict between nations. The laws of a country can be changed by revolts against existing political-legal structures, and the aspirations of individual citizens for greater ‘rights’ or freedom are an ongoing theme in the law.