The militias are composed of the same people. But it's the State militia. The Federal government is able to call it up if necessary, they were given a method to do so. But the militia isn't generally owned or armed by the federal government. The federal government has responsibilities to the State militias should they call them up. The State's responsibilities for their militias are different than federal. In general on the State side you are responsible for owning your own gun(s).