A constitution is a set of rules for governmentoften codified as a written documentthat enumerates and limits the powers and functions of a political entity. These rules together make up, i.e. constitute, what the entity is. In the case of countries and autonomous regions of federal countries the term refers specifically to a constitution defining the fundamental political principles, and establishing the structure, procedures, powers and duties, of a government. By limiting the government's own reach, most constitutions guarantee certain rights to the people. The term constitution can be applied to any overall system of law that defines the functioning of a government, including several uncodified historical constitutions that existed before the development of modern codified constitutions.
Constitutions concern different levels of political organization. They exist at national (e.g., codified Indian Constitution, uncodified Constitution of the United Kingdom), regional (e.g., the