A hygrometer is the instrument often used to measure humidity. This device quantifies the amount of moisture in the air, which is essential in various fields, including meteorology, construction, and science. There are several types of hygrometers, including analog ones that use materials that swell or shrink based on humidity and digital models that use sensors to provide precise measurements. Understanding humidity levels is crucial for predicting weather patterns, ensuring adequate indoor air quality, and even managing certain industrial processes.