A state constitution is a written document that outlines the framework and principles by which a particular U.S. state government operates, defines the powers and responsibilities of its different branches, and establishes the rights of citizens within the state. It serves as the foundation for the state's legal system and provides guidance on how laws should be made and enforced at both the state and local levels. State constitutions are typically adopted through a process involving the people of the state, either by direct vote or through their elected representatives in the legislature. They can also be amended over time to reflect changes in society's values and needs.