A turbidity sensor is a device used to measure the cloudiness or haziness of a liquid, often water. It works by shining a light through the liquid and detecting how much light is scattered by particles suspended in it. Higher turbidity levels indicate more particles, which can be caused by pollutants, sediments, or microorganisms. These sensors are commonly used in various applications, including environmental monitoring, water treatment, and aquaculture. By providing real-time data on water quality, turbidity sensors help ensure safe drinking water and maintain healthy ecosystems in bodies of water like rivers and lakes.