The Speaker of the House is the presiding officer of the United States House of Representatives. The office was established in 1789 by Article I, Section 2 of the United States Constitution, which states in part, "The House of Representatives shall choose their Speaker..."
The Constitution does not require that the Speaker be an elected House Representative, though every Speaker so far has been an elected Member of the House.
The Speaker is second in the United States presidential line of succession, after the Vice President and ahead of the President pro tempore of the U.S. Senate. Unlike some Westminster system parliaments, in which the office of Speaker is considered non-partisan, in the United States, the Speaker of the House is a leadership position and the office-holder actively works to set the majority party's legislative agenda. The Speaker usually does not personally preside over debates, instead delegating the duty to members of the House from the majority party. The Speaker usually does not participate in debate and rarely votes.
Aside from duties relating to heading the House and the majority political party, the Speaker also performs administrative and procedural functions, and represents his or her Congressional district.