Thin film interference occurs when light waves reflect off the surfaces of a thin layer, such as a soap bubble or an oil slick on water. When light hits the film, some of it reflects off the top surface, while some penetrates the film and reflects off the bottom surface. These two reflected light waves can interfere with each other, either amplifying or canceling out certain colors depending on their phase difference. The colors seen in thin films result from this interference effect. The thickness of the film, the angle of light, and the wavelength of light all influence which colors are enhanced or diminished. This phenomenon is commonly observed in everyday life, such as in soap bubbles and iridescent surfaces.