Federalism is a system of government where power is shared between a central authority and constituent political units. Key features include multiple levels of government that govern the same citizens but have distinct areas of jurisdiction, clearly defined revenue sources for each level, and a constitutionally guaranteed division of authority that can only be amended by consent of both levels of government. India has a federal system with legislative powers divided between the central and state governments across three lists: the Union List, State List, and Concurrent List. Decentralization further devolves power to local authorities.