Law is a set of rules created and enforced by social or governmental institutions to regulate behavior. The precise definition of law is controversial, but generally it involves a system of state-enforced rules that either expressly or implicitly govern relationships and activities among individuals and within the larger community. State-enforced laws may be made by a legislative body, producing statutes and other legislative instruments, or can arise from the executive branch in the form of decrees and regulations, or be established through case law in common law jurisdictions. Private individuals can also create legally binding contracts and arbitration agreements that have the force of law. Law serves several purposes, including establishing standards, maintaining order, resolving disputes, and protecting liberties and rights.

The most important function of law is to define the boundaries between the power of the state and the rights of the individual. The limits of the state’s power are defined by the rules of law, which ensure that people do not abuse their positions as servants of the state. Law also defines the rights of property and the relationships between people. For example, contract law regulates the ways that people exchange goods and services for value. Property law establishes the rights and duties of people toward tangible things they own, like houses and cars, as well as intangible property such as bank accounts and shares of stock.

Other important branches of the law include criminal law and civil law. Criminal law defines the crimes that a government can punish, while civil law deals with disagreements between individuals. Civil law encompasses everything from the right to compensation when someone’s property is harmed to divorce proceedings and child custody.

In addition, other fields of law address specific areas of the world or the economy. Environmental law is a growing field that addresses the effects of human activity on the natural environment, while maritime law and space law address issues in the oceans and outer space. Tax law and banking law concern how governments collect and distribute money and what rules banks must follow to protect depositors.

Many legal systems are rooted in religion. The Jewish Halakha, Islamic Sharia, and Christian canon law are all sources of legal doctrine. Moreover, some religious laws are explicitly based on religious precepts and cannot be amended by judges or governments. In other cases, religious law acts as a supplement to a more comprehensive legal system, such as the Roman and Germanic laws that exist on most continents today.