A soap bubble is a thin film of liquid soap that traps air inside, creating a spherical shape. The film is made up of water, soap, and sometimes other substances, which help stabilize the bubble. When light hits the bubble, it creates colorful patterns due to the interference of light waves reflecting off the inner and outer surfaces of the film. Soap bubbles are often used in science experiments to demonstrate concepts like surface tension and light interference. They can also be found in everyday life, such as when children blow bubbles using a bubble wand dipped in a soap solution.