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Traffic flow management, also referred to as air traffic management, is the craft of managing the flow of air traffic in the National Airspace System (NAS) based on capacity and demand. This differs from air traffic control (ATC) in that air traffic controllers, including traffic managers, strive to provide a safe, orderly and expeditious flow of traffic on a first-come, first-served basis.
Source: Concepts of Traffic Flow Management | NBAA – National Business Aviation Association
