Is DVDs invention or innovation

The DVD was a development rather than an invention. It was a high density version of the Compact Disc that was the first of the low cost optical storage devices. Similarly, the Bluray disc is a higher density version of the DVD.

The CD itself was a development of optical technologies with low power highly controllable lasers and plastics molding allowing CDs to be printed with accurate, tiny indentations. However, as the CD was the first of its kind, it can certainly be called an invention and so was the invention that lead to the DVD and then the Bluray discs.