The United States House of Representatives is the lower house of the bicameral United States Congress, the upper house being the United States Senate.
The composition and powers of the House and the Senate are established in Article One of the Constitution. The major power of the House is to pass federal legislation that affects the entire country, although its bills must also be passed by the Senate and further agreed to by the President before becoming law (unless both the House and Senate re-pass the legislation with a two-thirds majority in each chamber).
Each state receives representation in the House in proportion to its population but is entitled to at least one Representative. The most populous state, California, currently has 53 representatives. The total number of voting representatives is fixed by law at no more than 435. Each representative serves for a two-year term. The presiding officer of the House is the Speaker who is elected by the members of the House.
The Constitution grants the House several exclusive powers: the power to initiate revenue bills, to impeach officials, and to elect the President in case of an Electoral College deadlock.
The House meets in the south wing of the United States Capitol.
This above definition is sourced from Wikipedia, the free encyclopedia: http://en.wikipedia.org/wiki/United_States_House_of_Representatives
The U.S. House of Representatives also has its own information-rich website: http://www.house.gov/content/learn