The instrument used to measure wind speed is called an anemometer. Anemometers come in various designs, but the most common type consists of rotating cups or blades that capture the wind's force. The speed at which these cups or blades rotate is directly proportional to the wind speed. Meteorologists and weather stations often utilize anemometers to determine wind conditions, which are essential for weather forecasting and understanding local climate patterns. Additionally, anemometers are used in various fields, including aviation, marine, and environmental sciences.