The airline employees you see at the boarding gate are primarily called Gate Agents. Their job is a specialized branch of "Passenger Service Agents" or "Ground Staff." The Gate Agent is responsible for the final phase of the passenger journey before takeoff: they check boarding passes, verify passenger counts, handle seat upgrades or reassignments, and coordinate with the flight crew to ensure the "weight and balance" of the aircraft is accurate. They are also the primary point of contact for announcing delays, gate changes, and the boarding sequence. In addition to Gate Agents, you may also see Operations Agents who coordinate the "turnaround" of the aircraft, ensuring fuel, baggage, and catering are all loaded on time. In smaller airports or with budget airlines, a single person might handle both check-in and gate duties, while at large international hubs, these roles are strictly divided. While they are often the target of passenger frustration during delays, their main priority is safety and operational efficiency, acting as the final "gatekeeper" for the security and organization of every flight.
The Transportation Security Administration is an agency of the United States Department of Homeland Security that has authority over the security of transportation systems within, and connecting to the United States.