What is federalism?

What is federalism

The federal principle of government.

And federal means pertaining to or of the nature of a union of states under a central government distinct from the individual government of the separate states

A Federation is a set of states that are independent of each other, which have their own law (state constitutions) but which together adopt a central government to resolve national or foreign issues. Thus, the states of the Federation draw their constitution for their territory, with the necessary specificities while the National Government takes care of national affairs, which are what all states have in common. The US is a Federation. States are independent to establish their laws, but the Central Government takes care of national issues and the country's representation abroad. Therefore, Federalism is a system that aggregates several autonomous territorial entities with their own government in one state.