Law is a system of rules a society or government develops to deal with issues such as crime, business agreements and social relationships. The term is also used to refer to the people who work within this system. There are many types of law, including criminal, environmental and family laws. The laws can be made by a group legislature, resulting in statutes; by the executive through decrees and regulations; or through judicial decision, resulting in case law. Private individuals may also create legally binding contracts.

There are several different types of legal systems, depending on the historical and cultural context in which they developed. The most important factors in these differences are the governing power, the structure of the state and its culture, the role of religion and the extent to which it imposes control over society. In the modern world, the concept of the rule of law is central to the legitimacy of a state and its institutions. This concept includes measures to ensure the supremacy of law, equality before the law, accountability to the law, separation of powers and participation in the law-making process.

The law is a powerful tool to regulate human behaviour, and it is often viewed as a ‘normative science’. Hans Kelsen was one of the main proponents of this theory, and argued that law was a social science that provided guidance to human behavior.

In addition to regulating the activities of government, the law can protect the rights of individuals and groups. It can prevent the exploitation of minorities or the suppression of political opponents, and can facilitate social change. However, the role of the law is complex, and some legal systems serve these aims better than others.

Among the most important laws in recent history is international law, which regulates the relationships between nations and their citizens. It can help to resolve conflicts, prevent war and promote peace, and it can protect the environment, preserve natural resources and ensure the safety of travelers. It can even provide for a safe return to homelands after disasters such as earthquakes or hurricanes.

Legal practitioners are referred to as lawyers, and they can be employed by government agencies or private firms. They must undergo a formal process of education and training, and be regulated by the state or an independent regulating body such as a bar association or law society. Lawyers may use titles of respect such as Esquire, which denotes a barrister with high standing, and Doctor of Law, which indicates an academic degree in law. Some lawyers have also acquired other professional qualifications and achieved special awards.