A constitution is a fundamental set of principles or established precedents that outlines the structure and function of a government. It serves as the highest law of a country, defining the roles of different branches of government, such as the executive, legislative, and judicial branches. Constitutions also protect the rights and freedoms of individuals, ensuring that laws are applied fairly and consistently. Most countries have their own constitutions, which can be written or unwritten. A written constitution, like that of the United States, is a single document that clearly states the laws and principles. In contrast, an unwritten constitution, such as that of the United Kingdom, is based on statutes, legal conventions, and judicial decisions.