A mirage is an optical phenomenon that occurs when layers of air at different temperatures bend light rays. This bending creates the illusion of water or a reflective surface, often seen in deserts or on hot roads. The effect is caused by the refraction of light, which happens when it passes through air that varies in temperature. Mirages can be categorized into two types: inferior and superior. An inferior mirage appears below the horizon, making it look like water is on the ground, while a superior mirage appears above the horizon, often creating distorted images of objects. Both types are examples of how atmospheric conditions can trick the human eye.