Cloture is the procedural step of ending debate on a proposal and holding a vote to determine if it will pass. In the U.S. Senate, a three-fifths majority is usually required to invoke cloture, which translates to 60 votes if no vacant seats exist. If debating a change to procedural rules, an even larger two-thirds majority is required in the Senate. In the U.S. House of Representatives, a simple majority suffices to cut off debate.
A vote for cloture is the primary tool legislators have to defeat a filibuster. In practice, the filibuster and the subsequent cloture rule means that no law can pass the senate without a three/fifths majority of support.
The procedure outlining the cloture rule is found in U.S. Senate Rule XXII.
[Last updated in July of 2022 by the Wex Definitions Team]