Federalism is a political system in which power is shared between a central government and various constituent units, such as states or provinces. It is a system of government that is common in countries with large populations and diverse cultures, such as the United States, Canada, and India. Federalism is designed to balance the power of the central government with the autonomy of the constituent units, thereby ensuring that power is not concentrated in one place.

Key Features of Federalism:
1. Division of Powers: One of the key features of federalism is the division of powers between the central government and the constituent units. The central government is responsible for matters of national importance, such as defense, foreign policy, and currency, while the constituent units have the power to make their own laws and govern themselves on matters that are more local in nature.

2. Dual Government: Federalism is characterized by a dual government system, with power being shared between the central government and the constituent units. This means that both levels of government have their own separate spheres of authority, and they are not subordinate to each other.

3. Written Constitution: Federalism is usually based on a written constitution that outlines the division of powers and the relationship between the central government and the constituent units. The constitution serves as a legal framework for the operation of the federal system and provides a basis for resolving disputes between the central government and the constituent units.

4. Independent Judiciary: To ensure that the division of powers is respected and that disputes are resolved fairly, federalism typically requires an independent judiciary. The judiciary serves as a neutral arbiter in disputes between the central government and the constituent units, and it ensures that the constitution is upheld.

5. Shared Sovereignty: In a federal system, sovereignty is shared between the central government and the constituent units. While the central government has ultimate authority over matters of national importance, the constituent units have a degree of sovereignty over matters that are more local in nature.

In summary, federalism is a system of government in which power is shared between the central government and the constituent units. This division of powers is based on a written constitution and is supported by an independent judiciary. Federalism is designed to balance the power of the central government with the autonomy of the constituent units, thereby ensuring that power is not concentrated in one place.