Saiyar on 26 April 2008
The amount of Data that can be fitted on an optical disc is limited by the laser of the disc drive. For DVDs this limit is 4.7 GB per layer.
To get more data on the disc you need to make the pit size smaller. Beyond the 4.7 limit they are too small for the DVD laser to read.
Blu-ray drives laser has a short wavelength and great numerical aperture allowing for a tighter beam. The pits size can then be reduced allowing for more data to be stored per layer.
