Law is the aggregate of rules set by a society and enforced by its judicial system. It serves many purposes, including establishing standards, maintaining order, resolving disputes, and protecting liberties and rights. Law can be seen as a form of social control, and its precise nature is a subject of longstanding debate. It has been described as a science, an art, and a philosophy.

There are many different types of laws, ranging from statutes to regulations to case law. Some of the major fields include contract law, property law, torts, and criminal law. Each of these areas of law encompasses a wide range of topics and issues. Contract law covers the agreements that people make to exchange goods or services, such as buying a bus ticket or trading options on a stock market. Property law defines people’s rights and duties toward tangible property, such as land or buildings, and intangible property, such as bank accounts or shares of stock. Torts cover wrongful acts that cause injury or distress, such as an automobile accident or defamation of character. Criminal law deals with offenses against the state, such as robbery or murder.

The main function of any legal system is to define and enforce rules for all members of a society. Laws must be clear and consistent to be effective. This is particularly important for the field of contracts, where ambiguity could lead to disputes. It is also important for criminal and civil law, as the courts must be able to determine if a person has committed an offence. The judicial system must be objective and fair to be effective.

In some countries, the legal system is based on common law, in which case laws are determined by precedents established by the courts. This is known as stare decisis. The courts’ detailed records of similar situations and their outcomes are used to evaluate the law in new cases, and the decisions of higher courts and judges carry more weight than those of lower ones. In this way, the law is continuously refined as each case is decided.

Other systems of law are based on written statutes and regulations promulgated by government agencies. These systems provide a more complete and detailed framework for governing behavior, but they may not always be as clear as common law in their application of the principles. The reliance on judicial opinion, however, is a key strength of common law systems and enables parties (especially commercial) to predict what the law will be in certain situations, with reasonable consistency.

Some theorists, such as Hans Kelsen, have proposed a ‘pure theory of law’. The essence of this is that law does not attempt to describe what must happen, but merely defines the rules that people must follow. It is a ‘normative science’. However, the practical reality of judging is that judges are often influenced by personal beliefs and prejudices, and their interpretation of the law varies widely. Nonetheless, the judicial community does embrace objectivity and strive for fairness.