To be honest, in this post-9/11 world, any number of airline personnel might request to see your ticket. But traditionally, Russell probably presented his ticket to the clerk at the check-in counter. This is where the airline employee assigns him a seat number, prints out a boarding pass for him and checks in his baggage. From there, Russell would proceed to the appropriate gate number for his flight and wait for the boarding call. When boarding, he'll be required to show his boarding pass (not necessarily his ticket) to the gate attendant. He is then directed to board the aircraft. But usually the only place where you present your actual ticket is at the check-in desk at the airport; after that you are issued a boarding pass, which serves as your "ticket" after the fact.
Student or Learner