Federalism basically means government, and how things are working in the government . Back in the day there used to be dual federalism. Basically governments strictly divided into to the state government and the national government.

It’s not the separation of power just to different governments in one country. Each government had its own powers, also can be called jurisdiction.

National government 

• Has power over internal improvements
• Like roads
• Canals
• Sub cites 
• Regulation over public lands
• Pattens, they offered protection to inventors 
• Controlled currency

State government

• Controls loss like property, loss, commercial loss, and even marriage laws
• Controls insurance
• Public health
• Education
• Decides what is a crime

They have a lot of power 

after the great depression, they created regulated federalism, or cooperative federalism. 

Cooperative federalism

• Now united government
• Gives money to the states for accepting laws for having a lot of people
• The more poor people estate has the more money they get
• States can now ask for money, but it was not really liked as much as poor people
• Made rules for the states they can ask politely or force it/mandate it

Then new federalism was created. It gave more power to the states.

• States canal do their own thing
• They created block grants states now decide what to do with their money
• They created devolution states make their own regulations

We are now in a mix of new federalism and cooperative federalism and United States is somewhat trying their best. But there’s never gonna be really a balance because the government doesn’t really wanna give up their special powers