Reconciliation
An expedited budget procedure that lets certain fiscal legislation pass the Senate by simple majority, without being subject to a filibuster.
Reconciliation begins with a budget resolution that instructs committees to report legislation changing spending, revenues, or the debt limit by a specified amount. The resulting bill gets privileged treatment in the Senate: debate is limited, so it cannot be filibustered, and it passes with a simple majority.
The trade-off is scope. Because the procedure exists to implement budget decisions, provisions that are not primarily fiscal can be struck under the Byrd rule. That constraint shapes what ends up in the bill as much as the vote count does.
Most major partisan tax and spending laws of the last three decades moved through reconciliation, because it is the route that does not require sixty votes.