What does turbulence mean in an aviation context?

In an aviation context, turbulence refers to rough, bumpy, or choppy air that can cause an aircraft to experience sudden changes in altitude and movement. This phenomenon occurs due to various factors, such as changes in wind speed and direction, atmospheric pressure, or weather conditions like storms. Turbulence can vary in intensity and can be caused by thermal currents, jet streams, or the aircraft's interaction with terrain or other atmospheric disruptions. Understanding turbulence is crucial for flight attendants, as they must ensure passenger safety and comfort during these periods of unstable flight.

The other options misrepresent turbulence; for instance, describing smooth flying conditions does not align with the definition of turbulence, nor does identifying it as a pre-landing stage or a process of cruising at altitude. Each of those definitions reflects a different aspect of flight that does not pertain to the uneven and sometimes alarming experience characterized by turbulence.