http://www.usconstitution.net/consttop_cnb.html .
by James Burns, J.W. Peltason, and Thomas Cronin (Prentice-Hall, Englewood Cliffs, NJ, 1984), and Constitutional Law by Daniel Hall (Lawyers Cooperative Publishing, Albany, NY, 1997).

There are three branches in the United States government as established by the Constitution. First, the Legislative branch makes the law. Second, the Executive branch executes the law. Last, the Judicial branch interprets the law. Each branch has an effect on the other.