What device is used to break up white light into its component colors?

A prism is a transparent optical device that refracts, or bends, light. When white light passes through a prism, it slows down at different rates depending on the wavelength of the light. This refraction causes the light to spread out into a spectrum of colors, which is commonly referred to as a rainbow. The process of dispersion occurs because the different colors of light have different frequencies and thus different indices of refraction when entering and exiting the prism.

In contrast, a filter is used to absorb certain wavelengths of light while allowing others to pass through, but it does not break light into its component colors. A lens primarily focuses or diverges light rays but does not separate them into multiple colors. A reflector simply directs light without altering its spectral composition. These functions differ fundamentally from that of a prism, which is specifically designed to separate light into its individual colors.