Law is a set of rules created by an authority that citizens must follow. If they break the rules, they may face punishment such as fines or jail time. The word law can also be used to refer to a specific rule or standard, such as the rule not to steal or the law against murder. It can also refer to the actions of someone acting with authority, such as a manager laying down the law to his or her employees or a politician stating his or her views authoritatively.
Law can serve a variety of purposes, including keeping the peace, maintaining the status quo, preserving individual rights and liberties, and providing for orderly social change. Different legal systems serve these purposes differently; for example, an authoritarian government may keep the peace by imposing its own arbitrary laws and then enforcing them through coercion. Alternatively, the law may serve its purpose through a system of checks and balances between different branches of the government or between the government and the private sector.
Generally speaking, there is no single definition of law; it differs from person to person and from country to country. A few key elements that most definitions share are that the law should be easily understood and complied with, that it is publicly promulgated, equally enforced and independently adjudicated, and that it should guarantee core human and procedural rights. The concept of the rule of law, a standard that has been pushed by political philosophers and jurists, adds three more elements: that the law should protect against anarchy and Hobbesian war of all against all; that it should provide ways for people to predict the legal consequences of their actions; and that it should guarantee against at least some forms of official arbitrariness.