The United States government set up by the U.S. Constitution is divided into three branches with distinct roles -- the legislative branch, the executive branch and the judicial branch. The legislative branch is further divided into two chambers of Congress. The Senate is known as the upper chamber and the House of Representatives is known as the lower chamber of Congress.

Two is Better Than One

The framers of the Constitution operated under the assumption that dividing the powers of government added checks and balances which would help prevent tyranny. They decided to form two houses of Congress to provide further checks and balances on the branch of government responsible for enacting and changing the nation's laws. In addition to legislative powers, the two chambers of Congress share the power of declaring war and oversight of the executive and judicial branches of government.

Upper Doesn't Mean Better

Although the Senate is referred to as the "upper chamber," it is considered equal to the House of Representatives. Both chambers must approve all legislation before it becomes law. The term "upper chamber" came about because the first Congress met in a single building in New York City. The Senate occupied a chamber on the top floor of the building while the House met in the lower chamber.

A Little More Equal

Although the two chambers of Congress are considered equal, the Senate has some distinctive features that cause individual senators to have more political clout than individual representatives. This stems from the fact that each state receives equal representation in the Senate -- two senators. This gives a senator from a small state equal legislative power with senators from larger states. By contrast, the number of representatives each state sends to the lower chamber is based on population, giving some states more clout in the House than others.

Senate Distinctives

In addition to the duties it shares with the House of Representatives, the Senate has a number of distinct duties. These include the authority to ratify treaties with foreign governments and the responsibility of presiding over all impeachment trials of federal officials. Article II of the Constitution, which deals with the executive branch of U.S. government, also gives the Senate the responsibility to advise and consent to the nomination of Supreme Court justices, federal judges, cabinet members and other presidential appointees. Senators serve six year terms, compared to two year terms for representatives. Qualifications for the Senate include being 30 years old, having been a citizen of the United States for nine years and living in the represented state.