Law is the body of rules and principles that regulates behaviour in a society. It serves a number of important purposes: establishing standards, maintaining order, resolving disputes and protecting liberties and rights. The precise nature of the law varies widely from nation to nation, because it depends on who has political power to make and enforce laws. This is why revolts against existing political-legal authority are a recurring feature of human history.
The study of the law is a key part of jurisprudence, legal philosophy and economic analysis, and raises complex issues of fairness and justice. The study of law is also the subject of a great deal of scholarly debate, with many important ideas and theories evolving over time.
A broad range of subjects fall under the law: contract law governs agreements to exchange goods or services, ranging from buying a bus ticket to trading shares on a stock market; criminal law deals with activities that are harmful to society; and family and property law concern marriage and divorce proceedings, the rights of children and the use of property in the event of separation. Property law includes rights in land (known as real property), and intangible property, such as intellectual property, trademarks and copyrights. Commercial law concerns the operation of companies and the legal rules governing business transactions.
The laws of a country are usually codified in statutes, which impose legally binding obligations on people and businesses. In countries with a common law system, decisions by courts are considered law on equal footing with statutes and regulations passed through the legislative process. This is known as the doctrine of stare decisis.