Diffraction occurs when light hits an obstacle, and then bends around the edge of the object. The light bends as shown in Figure 1. Figure 2 shows another light diffraction example through a slit in the board. Light is also a wave, so if it goes through a narrow slit or small hole, it changes from a plane wave to a spherical one. This transformation is the same as with waves of water. Diffraction describes that change in light's direction. As the light wave becomes spherical, it spreads, and weakens after surrounding a small object or passing through a slit, making it seem to fade.