How is a Rainbow Formed?

A rainbow is formed when sunlight is refracted, or bent, as it enters a water droplet, then reflected off the inside surface of the droplet, and finally refracted again as it leaves the droplet. This process separates the sunlight into its constituent colors, creating the familiar spectrum of red, orange, yellow, green, blue, indigo, and violet. Each color has a different wavelength and is refracted by a different amount, leading to the colorful display we see in the sky. This phenomenon can be explained using the principles of physics and the behavior of light.