A blu-ray player can play blu-ray discs. Blu-ray discs can only about five times as much as a DVD ... I believe a DVD can do high-definition, but it would take up so much room that they would have to have it at least a quad-layer. A dual-layered blu-ray disc can hold about 50 Gigs, and not just hold as much as DVD in high definition, it can hold MORE. What would take two dual-layered DVD discs would take only one dual-layered Blu-ray disc.