Law is a set of rules that are enforced by society and government to control behavior. These rules are often written but can also be verbal or unwritten. They may govern everything from private property to the use of force in resolving disputes. In general, laws are intended to protect people and the environment from harm.

The exact definition of law is a matter of debate. However, many scholars have defined it as a tool of social control. Others have viewed it as a way to promote economic interests and ethical values. The sociologist Roscoe Pound took this further, defining law as the product of the struggle between conflicting pulls of political philosophy, economic interest and legal technique.

Another common definition of law is a system of rules, standards and principles that govern human conduct. This includes criminal and civil laws, as well as the rights and responsibilities of individuals and groups. It can be applied to the actions of private citizens, groups or the government itself. It may be based on morals or on the fact that a certain action violates the basic rights of an individual or group. In either case, it is enforceable through the threat of force or power.

Most governments use the law to achieve one or more of the following goals: establishing standards, maintaining order, resolving conflicts, and protecting liberties and rights. Some systems of law serve these purposes better than others. For example, an authoritarian regime may keep the peace and maintain the status quo, but it will likely oppress minorities or political opponents.

Other laws are based on religious precepts, such as Jewish Halakha and Islamic Sharia. These laws are often derived from divine scripture, but they also rely on further human elaboration through interpretation, Qiyas (reasoning by analogy) and Ijma (consensus).

Law can be applied to private or public behavior. It can be enacted by a legislature, resulting in statutes; by the executive branch, resulting in decrees or regulations; or created by judges through precedent in common law jurisdictions. It is also possible for private individuals to create their own legally binding contracts.

Several theories of law have been proposed, including legal positivism, natural law, and socio-economic theory. Some scholars believe that laws are created and enforced in a complex and dynamic process, with each phase requiring the active participation of individuals. Others, particularly those who subscribe to legal positivism, argue that the concept of law is an artificial construct that is created by humans.

A key principle of law is that people must be held accountable for their actions by a transparent and impartial process. This requires clear and accessible laws that are publicly promulgated, equally enforced, and stable over time. It also requires mechanisms to prevent abuse of power, such as a free and independent press and separation of powers. It also ensures that core human, procedural and property rights are protected. The rule of law is a necessary protection against anarchy and the Hobbesian war of all against all.