Rain sensors are devices designed to detect the presence of rain. They are commonly used in irrigation systems to prevent unnecessary watering when it is raining. By sensing moisture in the air or on surfaces, these sensors can automatically shut off sprinklers, conserving water and ensuring that plants receive the right amount of hydration. These sensors typically consist of a moisture-sensitive element and a control unit. When rain is detected, the control unit sends a signal to stop the irrigation system. This technology is beneficial for both residential gardens and larger agricultural operations, promoting efficient water usage and reducing waste.