What phenomenon occurs when light passes through a prism and displays a band of colors?

When light passes through a prism, it undergoes a process called dispersion, which results in the formation of a spectrum. This occurs because different colors of light have different wavelengths and are refracted, or bent, by different amounts as they pass through the prism's material. This separation of light into its constituent colors creates a beautiful band of colors typically ranging from red through orange, yellow, green, blue, indigo, and violet, commonly referred to as a rainbow or visible spectrum.

The term "spectrum" precisely describes this band of colors produced by the rainbow effect as light is dispersed. The phenomenon highlights a key aspect of optics and the nature of light, demonstrating how it interacts with materials like glass. While other processes such as refraction are involved in changing the direction of the light, it is specifically the dispersion due to refraction that leads to the creation of the visible spectrum when light enters and exits a prism.