Federalism is a political structure that divides power between a central government and subnational entities, such as states or provinces. This system allows for varying degrees of autonomy, enabling local governments to address regional issues while ensuring a cohesive national policy. The distribution of powers is often defined in a written constitution, outlining the responsibilities and authority of each level of government. Federalism promotes political participation and accommodates diversity within a nation, making it possible to address local needs while maintaining overall unity.