Law is the system of rules that governs human interactions and relations. It can be state-enforced through legislative statutes; by executive decrees or regulations; or, in common law jurisdictions, by judicial precedent. Law can also be privately enforced through contract, arbitration agreements and other means. Whether state-enforced or private, laws serve many purposes, but four principal ones are establishing standards, maintaining order, resolving disputes and protecting liberties and rights.
Legal systems differ from country to country, but all share the same basic purpose of regulating society and providing a framework for ensuring a peaceful, prosperous, equitable life. Some of the most significant differences in law are how the power to make and enforce laws is derived and distributed. In most nation-states, those who have the political and military power can create a legal system that serves their own interests or those of their group; the rest will be forced to follow that law, even if they disagree with it.
Those who wish to change the law must often first gain power through democratic elections or popular revolts. Once in power, they can then reshape the legal landscape by removing or altering existing statutes and creating new ones. They may also impose or enforce various social restrictions, such as censorship, crime and punishment and the use of force in war.
In a democracy, societal changes are usually accomplished through the legislative process and are guided by a constitution that sets forth fundamental principles. In authoritarian states, the ruling dynasty or dictator establishes the law. Laws can also be created and enforced by religious or other groups, but such laws are not normally accepted in democracies because they tend to be dictated by a single person or group and do not reflect the needs of the general population.
Many people have different ideas about what law is, and the precise definition is a subject of longstanding debate. Some legal scholars have argued that the law is simply “a set of rules imposed by the state to ensure the peace and prosperity of a community.” Others have defined the word more broadly, calling it a general code that regulates human relationships and transactions and lays the foundation for civilization. A third group sees the law as a system of moral principles that is applied to all members of a society to protect individual liberty, impose moral values and promote social justice. Regardless of its precise definition, the study of law is an important academic discipline.