A federal system of government typically includes the following characteristics:
Power is divided between a central (national) government and state/provincial governments.
There is a written constitution that outlines the distribution of powers and responsibilities between the central and state governments.
There is a system of checks and balances between the different branches of government (executive, legislative, and judicial) at both the national and state levels.
The central government has the power to make laws on certain matters (such as foreign affairs and national defense), while the state governments have the power to make laws on other matters.
There is often a Supreme Court or similar body that is responsible for interpreting the constitution and resolving disputes between the central and state governments.