What does 'Stacking' mean in aviation terms?

In aviation terms, 'Stacking' refers to the practice of holding aircraft at different altitudes in a holding pattern, typically executed when the aircraft cannot land immediately due to traffic or other restrictions. This method allows air traffic control to efficiently manage arrivals by maintaining safe separation between aircraft that are preparing to land. Each aircraft is assigned a different altitude to ensure they do not interfere with one another while awaiting their turn to descend and land at the airport.

The correct understanding of stacking is essential for maintaining safe operations in busy airspaces.