Written vs. Unwritten Constitutions: A written constitution is contained in a single document (e.g., the U.S. Constitution), while an unwritten constitution is based on statutes, conventions, and judicial decisions (e.g., the British Constitution).
Flexible vs. Rigid Constitutions: A flexible constitution can be amended easily, often through a simple legislative process, whereas a rigid constitution requires a more complex amendment process, making it more difficult to change.