Colorless or white light as perceived by human eye actually consists of many colors or wavelengths of light. Shown here is a beam of white light passing through a diffraction grating. Diffracted light propagates along discrete directions, called diffraction orders. The zeroth order does not exhibit dispersion (white beam). The light diffracted into the +1 and -1 diffraction orders is dispersed (decomposed) into different colors. Also visible but faint are the +2 and -2 diffraction orders.