The statement from a traveler wanting to check in for a flight in an airport check-in kiosk application is an example of a use case, which describes the interaction between a user and a system to achieve a specific goal.
The statement "As a traveler, I want to check in for a flight so that I can fly to my destination" is an example of a use case. A use case is a description of a system’s behavior as it responds to a request that originates from outside of that system. In this case, the system is the airport check-in kiosk application and the external request is initiated by the traveler who wants to use the application to check in. This maps out how a user (the traveler) interacts with the system (the application) to achieve a goal (checking in for a flight).