Here are examples of how the U.S. system of checks and balances works:
First, a new piece of legislation is introduced by a member of Congress who must convince a majority of the representatives and senators to pass the bill. The bill then goes to the President, who decides whether he thinks the bill is in the interests ofthe country. If so, he signs the bill, and it becomes a law.
If the President does not believe the bill is good for the country, he does not sign it into law. This is called a veto. The legislative branch gets another chance, though. If they can convince two-thirds of the members of the House and two-thirds of themembers of the Senate to pass the bill again, they can override the President's veto and the bill becomes a law.
Once a law is in place, the people of the country can test its validity through the court system, which is under the control of the judicial branch. If someone believes a law is unfair because it goes against the spirit or intent of the Constitution, alawsuit can be filed. Lawyers then make arguments for and against the case, and a judge decides which side has presented the most convincing arguments. The side that loses can choose to appeal to a higher court, all the way up to the Supreme Court. Decisionsof the Supreme Court set precedents or new ways of interpreting the law. Precedents form the basis of legal arguments that lawyers use to argue their cases.
If the legislative branch does not agree with the way in which the judicial branch has interpreted the law, they can introduce a new piece of legislation, and the process starts all over again.