Law is the set of rules a government or group of people develops in order to deal with things like crime, business agreements and social relationships. It is also the study of these systems of rules and their application in particular situations. Governments may enforce laws by directing police or courts to act, and they may punish people who break them, such as by fines or imprisonment. Different countries have varying approaches to law, but they typically share a common set of principles and concepts.
In modern society, laws are generally written by politicians in a legislature, such as parliament or congress, and passed (voted on) by the people they govern. Often these are based on a constitution that sets out the overall framework of the nation’s laws, and then additional laws are made for matters of detail. The law covers a wide variety of topics, including criminal law, property law and contract law.
A key debate about law is the extent to which it incorporates morality, with philosophers such as Jeremy Bentham advocating utilitarian theories of justice and Jean-Jacques Rousseau arguing that there are essentially morally unchangeable laws of nature. These debates have influenced the development of a range of legal theories, from John Austin’s utilitarian approach to more recent work by philosophers such as Thomas Aquinas and Sigmund Freud.
The practice of law includes a number of areas that vary by country, such as administrative law (which deals with the way a government is run), constitutional law and international law. Other areas of law that are more specific to a nation include labor law, medical law and family law.
In the United States, the main areas of law are federal law and state law. Federal law focuses on areas that the Constitution specifically grants authority to the government, such as the military, money and foreign policy, and regulations relating to interstate commerce and intellectual property (like patents and copyrights). State law can focus on anything from public health, to zoning and land use laws.
A central part of the law is the judiciary, which consists of judges who resolve disputes and determine whether people accused of crimes are guilty or innocent. The judiciary primarily uses the evidence presented in a case to make their decisions. Depending on the country, this system may also involve a jury or a panel of people, and in some cases, a judge may direct the jury on how to interpret the facts based on the law. Appeals of court decisions may go up to higher courts, such as the Supreme Court. In some countries, the highest courts can remove laws that are considered unconstitutional. In other countries, the judiciary is separate from the executive and legislative branches of government. This is known as a common law system. In this type of system, judicial decisions are binding on lower courts through the doctrine of stare decisis. This is unlike many civil law systems, where decisions by judges are not binding on lower courts.