There are 3 branches of government:
1. Legistlative
2. Judicial
3. Executive
They all use checks and balances.
The founding fathers envisioned this to prevent having a government that was too powerful.
An example would be passing a law. The legslative writes the law, the executive branch approves the law, and the judicial branch makes sure that the law is constitutional.
Hope this helped :) Good luck!