How far do your low beams and high beams shine?

Can someone explain the reasons why when you shine a laser beam into a cd or dvd, multiple beams are reflected?

• I know that when you shine a laser into these data disks a diffraction pattern is observed. And that this pattern which one sees depends on the wavelength of the laser light and the amounts of slits found on a disk. However what exactly makes these laser beams reflect the way they do. And why do i see a different pattern in a DVD against a Cd or even Blu ray? (I am using red and green lasers if that helps) The more detail your answer is, the easier i think i will understand.

• Answer:

  Because of diffraction in physics, look up interference pattern