A set of rules governing human conduct enforced by a controlling authority, often through penalties. Law is a social construct that shapes politics, economics, history and society in many ways. It is often regarded as the foundation of civilisation.

The precise nature of law is a subject of ongoing debate, with some commentators seeing it as a system of commands and prohibitions, and others viewing it as a more broader framework of rights and obligations. The most important aspects of law are those which establish standards, maintain order, resolve disputes and protect liberties and property.

Laws may be imposed by a group legislature, resulting in statutes; by the executive, through decrees and regulations; or established by judges through precedent, usually in common law systems. Private individuals may also create legal contracts and arbitration agreements that adopt alternative ways of resolving disputes to standard court litigation.

Generally, the laws of a country are derived from a constitution and the rights encoded within. Some countries use a common law system, where judgements are based on the interpretation of previous cases that have been brought before the courts (case law), while others employ a civil law system, where codes specify exactly how judges must decide a case.

There are a wide range of laws, covering almost every aspect of life, from civil procedure to criminal law to labour law to the rules governing marriage and divorce. Some of these laws are very specific, such as the tax code or copyright law, while others are more general, such as the rule of law or constitutional law.

The development of law is often influenced by political structures, including the existence or absence of a written constitution and the way in which power is distributed between central government and individual states. It can be shaped by social justice concerns, such as the need to ensure that people are treated fairly. It can be influenced by a desire to promote certain types of behaviour, such as the need for a minimum wage or to prohibit certain forms of discrimination.

In addition, laws can be influenced by religious precepts, such as Jewish halakha or Islamic Shari’ah. Some religions also have their own sources of law, such as Christian canon law or Islamic fiqh. Typically, these sources of law are more detailed than statutory or common law. However, they do not normally take precedence over statutory or common law in their application. In some fields, such as aviation and railways, federal statutes can supersede state laws. In others, such as family law or bankruptcy, laws at both the federal and state levels coexist. See articles on legal profession; legal education; and law in context. ‘Law in context’ refers to the relationship between the law and other areas of the social sciences. For example, see behavioural law; sociology of law; and law and social science. For a discussion of the history of law, see history of law. For more on the importance of law, see legal system; legal philosophy; and legal studies.