A humidity sensor is a device that measures the amount of moisture in the air. It works by detecting changes in electrical resistance or capacitance caused by humidity levels. These sensors are commonly used in various applications, including weather stations, HVAC systems, and industrial processes, to monitor and control humidity for comfort and efficiency. There are different types of humidity sensors, such as capacitive, resistive, and thermal. Each type has its own method of measurement and is suited for specific environments. Accurate humidity readings are essential for maintaining optimal conditions in places like greenhouses, museums, and laboratories, where moisture levels can significantly impact the quality of materials and products.