A filibuster is a tactic that can be employed by a Senator, or a group of Senators, that is allowed by the rules created by the Senate itself. A filibuster essentially is an obstructive tactic that is employed in the attempt to prevent for a particular motion or resolution to be brought to a vote by the members of the Senate.
Though there are several types of filibuster, the most commonly used involves the Senator extending the debate. Senators can literally speak for as long as they want and about any particular topic they choose. The only way to successfully end a filibuster is by achieving a three-fifths vote of the chamber to put an end to the debate. The longest filibuster in the history of the Senate lasted a total of twenty-four hours and eighteen minutes.