What word does your mother always say?
a system of constitutional government which guards against absolute power by providing for separate executive, judicial, and legislative bodies who share powers and thereby check and balance one another
A fundamental principle of American government, guaranteed by the Constitution, whereby each branch of the government (executive, judicial, and legislative) has some measure of influence over the other branches and may choose to block procedures of the other branches. Checks and balances prevent any one branch from accumulating too much power and encourage cooperation between branches as well as comprehensive debate on controversial policy issues. For example, to enact a federal law, the Senate and the House of Representatives must each vote to pass the law. In this sense, each house of Congress can check the other. Furthermore, even if the two houses do agree, the president must sign the law. If he chooses to veto the law, it can still be enacted if two-thirds of the members of both houses vote to override the veto. Under this arrangement, both Congress and the president can check each other. (See also appropriation, impeachment, judicial review, and separation of powers; also see chart, next page.)