A constitution is a set of fundamental principles or established precedents according to which a state or other organization is governed. These rules together make up, i.E. constitute, what the entity is. When these principles are written down into a single document or set of legal documents, those documents may be said to embody a written constitution; if they are written down in a single comprehensive document, it is said to embody a codified constitution. Some constitutions (such as the constitution of the United Kingdom) are uncodified, but written in numerous fundamental Acts of a legislature, court cases or treaties.
Constitutions concern different levels of organizations, from sovereign states to companies and unincorporated associations. A treaty which establishes an international organization is also its constitution, in that it would define how that organization is constituted. Within states,