Blu-ray is the next generation of optical disc technology. Although it is the same physical size as a traditional DVD, the Blu-ray Disc® holds five times the amount of data. A single-sided Blu-ray disc will hold approximately 25 GB of data; a dual-layer disc will hold up to 50 GB. That translates to around nine hours of high-definition (HD) or 23 hours of standard-definition (SD) video on a single dual-layer disc. Blu-ray technology uses a blue laser rather than the traditional red laser to burn an image (hence the name). This technology allows the data to be packed much more tightly on the disc, eliminating the need to increase the disc size. The Blu-ray ROM drive can play BD-R/RE or BD-ROM as well as read or write to CDs and DVDs.