China Blue High-definition Disc China Blue High-definition Disc China Blue High-Definition (CBHD; ; alternatively "China High Definition DVD") is a high definition optical disc format announced in September 2007 by the Optical Memory National Engineering Research Center (OMNERC) of Tsinghua University in China. The format is a derivative of the HD DVD, a medium created by the DVD Forum designed to succeed regular DVDs. Although HD DVD was scrapped as a result of losing the format war to Blu-ray, CBHDs continued to be produced and marketed, though only in China. Originally called CH-DVD, CBHD is a joint venture between the DVD Forum and OMNERC.
Optical disc current third-generation discs and have the potential to hold more than one terabyte (1 TB) of data and meant for distributing Ultra HD video : There are numerous formats of optical direct to disk recording devices on the market, all of which are based on using a laser to change the reflectivity of the digital recording medium in order to duplicate the effects of the pits and lands created when a commercial optical disc is pressed. Formats such as CD-R and DVD-R are "Write once read many", while CD-RW and DVD-RW are rewritable, more like a magnetic recording hard disk