DVD - Digital Video Disk or Digital Versatile Disk
  An improved version of the CD

  Red laser 
     650 m (red/orange) DVD vs. 780 N (near infra-red) for CD

     Tighter spiral (0.74 micron gap vs 1.6 micron for CD)

     Smaller pits (0.4 microns vs 0.8 microns for CD)

     Thinner recording layer allows multiple layers.


  Encoding and error correction more efficient (fewer overhead bits)

  Provides for a 7 fold increase of capacity.
 
  Increased linear speed( 1.4MB/sec vs 150KB/sec for CD)