DVD vs. Blu-ray looks like a simple size upgrade, but the real gap between the two formats hides in the light and the numbers ...

Plenty of physical video formats have hit the mainstream over the years and decades - here are the most popular ones, ranked.

The high-definition movie disc battle between HD DVD and Blu-ray Disc can be traced all the way back to 2000, when companies began experimenting with using new blue lasers in optical disc systems.

DVDs and CDs, the magical shiny discs that somehow played music and movies, were the première form of multimedia in the 1990s ...