A filibuster is a legislative tactic used in the U.S. Senate to delay or block a vote on a bill or nomination by extending debate on the matter. Senators can engage in extended speeches or other forms of obstruction to prolong discussions, which can effectively prevent a vote from taking place. Traditionally, a filibuster requires a supermajority of 60 votes to overcome, although recent changes have allowed for certain nominations to be confirmed with a simple majority. It is often used as a tool by the minority party to express dissent or influence legislation.