An airspeed indicator is an essential instrument in an aircraft that measures the speed of the aircraft relative to the surrounding air. It displays the speed in knots or miles per hour, helping pilots understand how fast they are flying. This information is crucial for safe takeoff, landing, and overall flight performance. The airspeed indicator works by comparing the pressure of the air entering a tube on the aircraft's exterior to the static air pressure. This difference in pressure is converted into a speed reading. Accurate readings are vital for maintaining control and ensuring the safety of the flight, especially during maneuvers and adverse weather conditions.