A hygrometer is an instrument used to measure the humidity level in the air. Humidity refers to the amount of water vapor present in the atmosphere, which can affect weather, comfort, and even health. Hygrometers come in various types, including analog and digital models, and are commonly used in meteorology, agriculture, and indoor climate control. These devices work by using different methods to detect moisture. For example, some hygrometers use a material that expands or contracts with humidity changes, while others rely on electronic sensors. Accurate humidity readings are essential for applications like weather forecasting, greenhouse management, and HVAC systems.