What does the term 'groundspeed' refer to?

Groundspeed refers to the speed of an aircraft as it moves relative to the ground beneath it. This measurement is important for flight operations as it directly affects the time it takes to reach a destination and is influenced by factors such as wind. When the aircraft is flying with a tailwind, its groundspeed will be higher than its airspeed, while a headwind will decrease the groundspeed compared to airspeed. Understanding groundspeed helps pilots and flight planners determine flight times and fuel consumption more accurately.

In contrast, the other options focus on different aspects of an aircraft's performance, such as airspeed, fuel consumption, and wind effects, which are distinct from the measurement of groundspeed itself.