The U.S. Constitution divides the powers and the responsibilities of the government into three branches: the legislative, the judicial and the executive. The legislative branch is the one responsible for proposing, discussing and making laws. Once both chambers pass a law, it has to be sent to the President for signature. If the President signs it, the law is enacted, but if the President rejects it, the law goes back to Congress, who has a chance to override the President's veto if the law gets voted on by at least two-thirds of the members.
