Air quality sensors are devices that measure the levels of pollutants in the air, such as carbon dioxide, particulate matter, and volatile organic compounds. They help monitor the cleanliness of the air we breathe, providing valuable data for individuals and communities to understand their environment. These sensors can be found in various forms, including portable units for personal use and larger systems for urban monitoring. By collecting real-time data, air quality sensors play a crucial role in promoting public health and informing policies aimed at reducing air pollution and improving overall air quality.