A filibuster is a legislative tactic used in the U.S. Senate to prolong debate and delay or prevent a vote on a bill. Senators can engage in extended speaking or procedural maneuvers, effectively using time to negotiate or draw public attention to specific issues. The filibuster requires a 60-vote majority to overcome, making it a powerful tool for the minority party. It has far-reaching implications for legislative efficiency and can lead to significant political standoffs, impacting the legislative agenda and governance overall.