In the House, members of each party caucus meet on an informal basis within a week or two after the general election to organize and elect leaders. Each caucus can nominate a speaker designate. The speaker is officially elected by members of the entire House on the opening day of the session. The majority caucus also elects a majority leader and assistant leaders. Likewise, the minority caucus elects a minority leader to express the caucus opinion on the House floor, and other assistant minority leaders. For a list of current leaders in the House, see the House of Representatives Leadership web page.
In the Senate, the leader of the majority caucus directs the business of the Senate and is considered the leader of the Senate. He or she is elected by the members of the caucus, which also elects the leader's chief assistant, called the assistant majority leader. The minority caucus also elects its own leaders, much like the House does. The President of the Senate, who presides over the activities of the Senate and assigns bills to committees, is elected on the opening day of each biennial session. Senate leadership positions are noted on the Senate member page.
Whichever party holds the most seats in either the House or the Senate is considered the Majority Caucus.