An instrument used to measure the speed of wind is called an anemometer. Commonly used in meteorology and aviation, anemometers can take various forms, with the most popular being the cup and vane types. A cup anemometer consists of three or four cups that rotate on a vertical shaft, with the rotation speed correlating to wind speed. Vane anemometers involve blades that get pushed by the wind, providing an electronic output of wind speed. Measuring wind speed accurately is essential in fields related to weather forecasting, aviation safety, and environmental research.