Majority Leader:The Majority Leader is the floor leader of the majority party in either the United States House of Representatives or the United States Senate. They are responsible for setting the legislative agenda and coordinating their party's activities in the chamber.
Whip: The Whip is a member of a political party in a legislature whose primary task is to ensure party discipline on votes, by persuading members to vote according to the party platform.
Party Caucus: A party caucus is a meeting of the members of a political party in a legislative body, such as the United States Congress, to discuss party business and strategy.