An airline provides transport.
As of 2019, the largest airline by passengers carried and fleet size was the American Airlines Group, while Delta Air Lines was the largest by revenue
 Flight crew members include: pilots (captain and first officer: some older aircraft also required a flight engineer and/or a navigator); flight attendants (led by a purser on larger aircraft); In-flight security personnel on some airlines (most notably El Al)Groundcrew, responsible for operations at airports, include Aerospace and avionics engineers responsible for certifying the aircraft for flight and management of aircraft maintenance; Aerospace engineers, responsible for airframe, powerplant and electrical systems maintenance; Avionics engineers responsible for avionics and instruments maintenance; Airframe and powerplant technicians; Electric System technicians, responsible for maintenance of electrical systems; Flight dispatchers; Baggage handlers; Ramp Agents; Remote centralized weight and balancing; Gate agents; Ticket agents; Passenger service agents (such as airline lounge employees); Reservation agents, usually (but not always) at facilities outside the airport; Crew schedulers

