When creating Congress, the Founding Fathers of the United States set out the powers and limits of the House of Representatives and the Senate, making it a bi-cameral system with power shared between the two houses.

The Senates role in this bi-cameral system of Congress is to: ratify Presidential appointments and foreign treaties and tries the impeachment of a President. Filibusters also happen in the Senate.

The President has the right to nominate individuals into positions throughout the government. From judges, administrative positions and secretaries in a range of agencies. Article two, Section two of the US Constitution gave the Senate the right to give consent to every nomination, as well as suggesting other nominees for those positions and the final vote to accept or decline the nomination. A nominee only needs a simple majority of votes for the position.
An example of the Senate confirming an appointment would be the replacement of Supreme Court Justice, John Paul Sanders in 2010. Sanders was replaced by Elena Kagen. The vote was 63 to 37, 58 being Democrats and 5 being Republicans.

The Senate alone has the right to give consent and advise to the President for all National Treaties.; once signed by the President, a treaty has to go to the Senate (the Senate Committee of Foreign Relations). The Senate will then assess the benefits of the treaty to the US and then come to a vote. 67 votes or two thirds of the 100 Senators are needed for the President to then move on with the ratification of the treaty.
In December 2012 a vote was held to ratify a U.N. treaty on disabilities. The treaty promoted equal rights for disabled people around the world, yet the vote of the Senate fell short. 61 votes were in favour of passing this treaty, 6 less than the required 67, so this treaty was not able to go through.

The process if impeachment begins in the