Blu-ray Disc recordable

BD-R and BD-RE are recordable and rewritable versions of the Blu-ray Disc format, allowing video, audio or data to be written directly onto Blu-ray media with a suitable recorder. A BD-R disc can be written only once, while a BD-RE disc can be erased and rewritten many times, in the same way CD-R and CD-RW differ. Capacities range from 25 gigabytes on a single layer disc up to 50 gigabytes on a dual layer disc, with the BDXL variants reaching 100 gigabytes on three layers and, for BD-R only, 128 gigabytes on four layers. The specification sets a minimum write speed of 36 megabits, about 4.5 megabytes, per second.