Law is a set of rules created and enforced by the state to ensure a peaceful society. These laws can be created and enforced by a variety of mechanisms, and sanctions can be imposed when the laws are broken. Laws are important to societies for several reasons, including establishing standards, maintaining order, resolving disputes, and protecting individual liberties and rights. Some legal systems serve these purposes more effectively than others. For example, an authoritarian regime that is based on the rule of law may keep the peace and maintain the status quo, but it might also oppress minorities or restrict social change (as in Burma under Aung San Suu Kyi).
The precise definition of Law is difficult to pin down, as different legal systems have their own philosophies and concepts. However, there are some common features of laws: they can be enacted by a legislature through statutes; by an executive through decrees and regulations; or by judges through precedent, in common law systems. The latter is the basis of the doctrine of stare decisis, whereby decisions by higher courts bind lower ones to assure consistency in judicial decision-making.
Other laws are more specific, for instance environmental law deals with the protection of the environment through regulations and penalties. Aviation law outlines all the regulations and technical standards that must be met for the safe operation of aircraft. Labour law concerns the tripartite relationship between worker, employer and trade union; civil procedure involves the rules that must be followed as a trial or appeal takes place; and evidence law determines which materials are admissible in court.