This document defines and describes different types of constitutions. It explains that a constitution serves as the fundamental law that structures a government and protects citizens' rights. Constitutions can be written or unwritten, enacted by a group or evolved over time, and more or less difficult to amend. Written constitutions explicitly lay out rules, while unwritten ones rely more on tradition. Enacted constitutions are deliberately created while evolved ones develop gradually. Rigid constitutions have stringent amendment procedures, whereas flexible ones can be modified like ordinary laws.