What does it mean if an aircraft has a high "Ground Speed"?

Ground speed refers to the speed of an aircraft relative to the ground below it. Therefore, when an aircraft has a high ground speed, it indicates that the aircraft is moving rapidly over the surface of the earth. This measurement is crucial for flight operations, as it affects flight planning, fuel consumption, and overall travel time.

While cruising altitude can be relevant to the aircraft’s performance, it does not specifically correlate with ground speed. Likewise, strong headwinds would reduce ground speed, and an aircraft approaching landing typically has a lower ground speed as it descends. Thus, a high ground speed directly signifies the aircraft's rapid movement across the terrain, making it the clear choice in this context.