Law is a system of rules created and enforced by social or governmental institutions to regulate behavior and protect people and property. Its precise definition is a longstanding subject of debate, but it generally includes both the rules themselves and their enforcement, with the word “law” also being used to refer to the profession of lawyers and judges (see jurisprudence). Rules can be made by a group legislature, resulting in statutes; by the executive through decrees or regulations; or by the courts through precedent, especially in countries that have a common law tradition. Private individuals may also create legally binding contracts, and arbitration agreements that adopt alternative ways of resolving disputes to standard court litigation.
The main functions of the law are establishing standards, maintaining order, resolving disputes and protecting liberties and rights. Different societies require different types of laws and systems of law to serve these purposes, but the general aim is for a legal system to make sure that all members of society are treated fairly. The specifics of how this is accomplished vary widely from nation to nation, although most modern nations have a constitution that specifies the fundamental principles of their law.
Many types of law exist to meet the diverse needs of societies, and each discipline within law has its own special features. Contract law, for example, concerns enforceable agreements, including those that involve money; the field of property law encompasses rights and duties to tangible objects such as houses or land (known as real property) and movable objects, like computers or cars (called personal property); and intellectual property laws address everything from patents to copyrights.
Other areas of law include aviation law, which involves the regulations and safety standards that pilots must follow; employment law, which covers the tripartite relationship between worker, employer and trade union; and environmental law, which penalises polluters within domestic legal systems. Banking law focuses on rules that banks must follow to maintain capital reserves and avoid financial crises; competition law, which aims to control companies who use their economic power to distort market prices, has roots in Roman decrees against price fixing and English restraint of trade legislation; and administrative law relates to the rights and responsibilities of citizens as well as to the operations of governments themselves.
Each of these broad fields has subfields, and there are numerous other specialist branches of law, such as family law, which encompasses marriage and divorce proceedings; labour law, which involves the tripartite relationship between worker, employers and trade unions; and criminal law, which consists of the rights, punishments and procedures for prosecuting criminals. There is even a branch of law known as biolaw, which combines the study of law with the life sciences. The law permeates all aspects of human society, and there is a huge variety of careers available for those who wish to specialise in particular fields of the law.