Law is a set of rules created by a sovereign authority and enforced by mechanisms that ensure a peaceful society. It can be interpreted to mean anything from a statute, regulating a particular activity or industry, to an ordinance, enforcing some detail of procedure on a small scale, to a constitutional law, the body of laws governing a nation-state. Laws can be created by a legislature (legislators are members of parliament in the United Kingdom), a monarch, or an executive authority such as a president. They can also be imposed by force, a principle known as coercion or imperialism.
There are numerous branches of law, covering everything from the rights and duties of citizens to the ownership of land and money. Contract law governs agreements to exchange goods and services, from buying a bus ticket to trading options on a derivatives market. Property law covers people’s rights and responsibilities toward tangible things, such as houses or cars, whereas intellectual property laws govern intangible items like patents and copyrights. Criminal law focuses on the punishment of people who break social and moral codes. The legal profession is highly specialised, with titles such as Esquire to indicate barristers of higher rank and Doctor of Law indicating those who have obtained a PhD in Law.
The fundamental function of law is to serve the public interest, and this requires that all people, including government officials, are subject to the law. In contrast, an autocracy, oligarchy or dictatorship treats its rulers as above the law, which is a recipe for repression and civil unrest. There are many mechanisms for establishing and maintaining the rule of law, and these vary from country to country, but democracy is the most common form of governance.
Some of the most important laws are social in nature, and aim to promote human rights and social justice. The most prominent examples include human rights and the laws relating to discrimination, labour and property. There are also laws relating to the environment and the management of resources, such as water and energy.
Other laws are explicitly based on religious precepts, such as Jewish Halakha and Islamic Sharia. These laws rely on further elaboration, such as a combination of interpretation, Qiyas, Ijma and precedent, to create comprehensive legal systems. They may also contain ethical principles, such as the Golden Rule and the Ten Commandments.