A hygrometer is a device used to measure the humidity level in the air. Humidity refers to the amount of moisture present in the atmosphere, which can affect comfort, health, and even the condition of materials. Hygrometers are commonly used in homes, greenhouses, and weather stations to help monitor and control humidity levels. There are different types of hygrometers, including analog and digital models. Some use materials that expand or contract with changes in humidity, while others rely on electronic sensors. By providing accurate humidity readings, a hygrometer can help people maintain a comfortable environment and protect items like wood furniture and musical instruments from damage.