How is spectrum produced in a prism?

A prism produces a spectrum through the process of dispersion, which occurs when light passes from one medium (air) into another medium (glass). As light enters the prism, it slows down and bends at different angles depending on its wavelength; shorter wavelengths (like blue and violet) bend more than longer wavelengths (like red). This separation of light into its constituent colors creates a continuous spectrum, which is visible when white light passes through the prism. The resulting spectrum displays a range of colors from red to violet, illustrating the different wavelengths present in the light.