A constitution is a fundamental set of principles or established precedents that outlines the structure and function of a government. It serves as the supreme law of a country, defining the rights of citizens and the responsibilities of government officials. Constitutions can be written or unwritten and vary widely in their content and complexity. Most countries have a constitution that guides their legal and political systems. For example, the United States Constitution is a written document that includes the Bill of Rights, which guarantees individual freedoms. In contrast, the United Kingdom has an unwritten constitution based on statutes, conventions, and legal precedents.