A constitution is an aggregate of fundamental principles or established precedents that constitute the legal basis of a polity, organisation or other type of entity, and commonly determine how that entity is to be governed.
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 that 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 countries 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, a constitution defines the principles upon which the state is based, the procedure in which laws are made and by whom. Some constitutions, especially codified constitutions, also act as limiters of state power, by establishing lines which a state's rulers cannot cross, such as fundamental rights.
The Constitution of India is the longest written constitution of any country in the world, containing 444 articles in 22 parts, 12 schedules and 124 amendments, with 146,385 words in its English-language version. The Constitution of Monaco is the shortest written constitution, containing 10 chapters with 97 articles, and a total of 3,814 words.
The term constitution comes through French from the Latin word constitutio, used for regulations and orders, such as the imperial enactments (constitutiones principis: edicta, mandata, decreta, rescripta). Later, the term was widely used in canon law for an important determination, especially a decree issued by the Pope, now referred to as an apostolic constitution.