Activated carbon filters are special devices that use a form of carbon that has been treated to make it very porous. This means it has a large surface area, allowing it to trap impurities and contaminants from air or water. When air or water passes through the filter, harmful substances like chemicals, odors, and pollutants stick to the carbon, effectively cleaning the air or water. These filters are commonly used in various applications, such as in water purification systems, air purifiers, and even in fish tanks. They are popular because they are effective, affordable, and can help improve the quality of the environment around us.