Law is a set of rules created and enforceable by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate and it has been variously described as a science and as the art of justice. The modern notion of the rule of law reflects the insights of scholars such as Max Weber, who reshaped thinking on how government and private power could be held accountable.
Law has an impact on politics, economics, history and society in many ways and it acts as mediator between people. It can be based on religious precepts (for example the Jewish Halakha or Islamic Sharia), it can be derived from social customs (such as a judge-made precedent known as common law) and it can also be based on legislative codes that central bodies have codified and enforced.
Some countries that have no formal legal systems rely upon local customary law, while others have a combination of civil and common law. Civil laws are based on a code that has been developed and consolidated by legislative bodies, while common law is derived from judicial decisions. A growing number of countries are moving towards a combination of civil and common law.
The most important function of law is to promote and protect human rights and the democratic process. It can do this in a variety of ways including by upholding the constitution, prosecuting war criminals, protecting the environment and regulating trade. It can also be used to prevent discrimination, to provide equality of opportunity and to safeguard the health and safety of citizens.
Modern governments and agencies rely heavily on the law to control their activities, and to ensure that they do not abuse their power or interfere with freedom of speech, association, religion and privacy. In this role, the rule of law is an important counterbalance to the power of the state and it can help prevent tyranny and dictatorship.
The study of the law is called Jurisprudence and a person who practises the law is known as a lawyer or solicitor. In most jurisdictions, a lawyer has to be licensed by a professional body such as a bar association or law society and they can only be appointed to this status after passing a qualifying examination. The practice of law is overseen by these governing bodies to ensure that the public interest is served and that there are sufficient protections for clients and their lawyers. In addition, a lawyer will typically hold a degree in law (either a Bachelor of Laws, Bachelor of Civil Law or a Juris Doctor). Some universities offer postgraduate degrees in law. These can be Masters in Law or Master of Legal Studies. They may also be offered by specialist institutes such as the University of Melbourne, the London School of Economics or the New York City School of Law. The Law has a global reach and is a significant part of the international system of governance.