What defines a "thru passenger" on a flight?

A "thru passenger" is specifically defined as a passenger who remains onboard the aircraft during an intermediate stop. This could occur, for instance, when a flight makes a brief layover to pick up or drop off other passengers but does not require all passengers to deplane. Such passengers' travel itineraries are seamless, allowing them to continue their journey without changing planes or going through additional check-in processes.

Understanding this term is important for flight attendants, as it helps them manage passenger needs, provide service during flight delays, and ensure that all safety protocols are followed without the need for certain passengers to disembark. Other choices relate to different aspects of passenger travel, but they do not encapsulate the unique definition of a "thru passenger."