Blu-ray Blu-ray Blu-ray or Blu-ray Disc (BD) is a digital optical disc data storage format. It was designed to supersede the DVD format, and is capable of storing several hours of video in high-definition (HDTV 720p and 1080p) and ultra high-definition resolution (2160p). The main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, and Xbox One. The name "Blu-ray" refers to the blue laser (actually a violet laser) used to read the disc, which allows information to be stored at a
DVD-RAM The on-disc structure of DVD-RAM is closely related to hard disk and floppy disk technology, as it stores data in concentric tracks. DVD-RAMs can be accessed just like a hard or floppy disk and usually without any special software. DVD-RWs and DVD+RWs, on the other hand, store data in one long spiral track and require special packet reading/writing software to read and write data discs. Like magneto-optical (MO) technologies, DVD-RAM has numerous rectangles on the disc surface that define the boundaries of data sectors. However, DVD-RAM is not MO but a phase transition medium, similar to CD-RW, DVD-RW, or DVD+RW.