Law is a system of rules governing how people live and interact with each other. These are often enforced by the police or by courts and may include fines or prison time for breaking them. Laws cover all sorts of issues, from preventing people from driving while drunk to protecting the privacy of medical patients. Most countries have a written constitution which sets out core legal rights and duties. Some laws are voted on by elected representatives in a parliament or congress, while others are decided by judges or other court officials. Most countries also have lawyers, jurists or attorneys who specialise in certain areas of the law.
Law shapes politics, economics, history and society in many ways. It provides the framework for a society and allows for the transfer of power between different governments or groups of people, whether that is from the military to the government or from one party to another. It explains the relationships between citizens, defines property and personal rights, governs the distribution of resources and defines criminal behaviour. It also serves as a mediator between individuals.
One important issue in the law is the extent to which it incorporates morality. For example, a government might create a law requiring people to eat five portions of fruit and vegetables each day. But this is not a law in the same sense as a court order to arrest a person. Those who believe that morality is a part of the law sometimes argue that people should follow laws that are clearly immoral or unjust.
Other important issues in the law are how laws are made, how they are enforced and how they impact on equality of opportunity. Some philosophers have developed theories of the nature of law, including utilitarian theories based on a balance of competing interests, and natural law theory founded on an idea of a moral foundation for human law. The modern expansion of state power through armed forces, policing and bureaucracies poses special problems for the legitimacy of this type of authority that earlier writers such as Locke or Montesquieu could not have imagined.
A key issue in the modern law is how to measure and understand its effects. The science of law includes areas such as criminology, jurisprudence, sociology and philosophy. It is also increasingly concerned with societal impacts, for example on gender, race, religion, social class and ethnicity. In addition to academic study, the field of law is also highly practical and a career in law is a popular choice for young people.