An air filter is a device designed to remove impurities and particles from the air. It works by trapping dust, pollen, smoke, and other contaminants, improving indoor air quality. Air filters are commonly used in heating, ventilation, and air conditioning (HVAC) systems, as well as in air purifiers. There are various types of air filters, including HEPA filters, which can capture very small particles, and electrostatic filters, which use an electric charge to attract dust. Regularly changing or cleaning air filters is essential for maintaining their effectiveness and ensuring a healthy living environment.