What distinction is made between the status of 'astronaut' and mission-specific roles like 'Commander'?

Astronaut is the status of having flown, whereas Commander or Pilot is the role during a specific flight

A key insight into space nomenclature highlights the difference between a sustained classification and a temporary designation based on current assignment. 'Astronaut' generally signifies the status achieved by any individual who has successfully trained and flown in space, often representing a career classification developed through rigorous government training pipelines. In contrast, titles like 'Commander,' 'Pilot,' or 'Mission Specialist' define the specific operational role or job title assigned to that astronaut for the duration of a particular mission. This means a veteran astronaut could serve as a Mission Specialist on one flight after having commanded another, illustrating the fluidity between status earned and the role currently occupied.