The main purpose of a constitution is to outline the fundamental principles and rules governing a nation, establishing the framework for political authority and the rights of citizens. A constitution serves as the highest law of the land, guiding the operation of government, defining the separation of powers, and protecting individual liberties. It aims to provide stability, limit governmental power, and ensure accountability, promoting democratic governance. By delineating how laws are made, interpreted, and enforced, a constitution helps maintain order and justice within society.