The House of Representatives and the Senate are the two parts of the United States Congress. The Capitol in Washington, D.C. houses both of these bodies. Members of both are selected through the process of direct election. While most members of both houses come from the Republican or Democratic Party, a handful of members serve as independents or members of third parties.
Article I from the U.S. Constitution centers the legislative powers of the government in the Congress. No law can be enacted without both chambers consenting, although each house has several unique powers. For example, the Senate confirms presidential appointments and ratifies treaty agreements, while the House is the source of any bills to raise revenue. In the event of impeachment, the House has to initiate the case, and the Senate tries it. Two-thirds of the Senate must vote to convict an impeached person, removing him or her from office.
The number of seats that each state has in the House varies with the relative population of the states. Over the last couple of decades, much of the voting power has headed west and south. While the House gives people local representatives in the federal government, the Senate gives people of each state at-large representatives in the federal government.