What is Blu-ray Disc?

A blu-ray Disc (BD) is an optical disc which is next in-line to replace DVD as a data storage medium.It may also be regarded as a next generation of optical disc after DVD.Physically,it is a plastic optical disc having the same size as that of a dvd and a CD.However its data storage capacity is stupendously higher than that of a CD and a dvd.Physically a standard blu-ray disc is 12cm in diameter while a mini blu-ray disc is 8cm in diameter.A blu-ray disc may be single layered or dual layered.A standard blu-ray disc contains 25GBs of data storage capacity in a single layer.So, a dual layered blu-ray disc has a data storage capacity of 50GBs.A mini blu-ray Disc has a data storage capacity of 7.5GBs in a single layer.

blu-ray disc was developed by blu-ray Disc Association.blu-ray Disc Association is a group of companies which are involved with promotion and development of blu-ray Disc format.Which include consumer electronics and hardware manufacturers and makers of motion pictures.
The blu-ray disc has got its name from the blue laser that is employed to read from and write to the blu-ray disc.This blue laser used in reading a blu-ray discs has shorter wave-length than the red laser used in reading DVDs.Due to shorter wavelength of the the blue laser, used in reading from and recording to blu-ray discs,as compared with the red laser, used in reading from and writing to DVDs,it possible to store information in a blu-ray disc at a much higher density than a DVD.The wavelength of the laser that a blu-ray disc uses is 405nanometre while the wavelength of the laser that a dvd uses is 650nanometre.Due to the shorter wavelength of the blue laser used for blu-ray disc as compared with the red laser used for dvd,the data storage capacity of a blu-ray disc in a single layer is roughly more than five times the data storage capacity of a DVD in a single layer.

Almost all the major consumer electronics companies and almost all the leading computer and blank media producers are supporters of blu-ray disc format. According to the website of  Blu-ray Disc Association ,currently there are 150 companies which are members of Blu-ray Disc Association.   
Typical applications of blu-ray Disc are in High Definition TV recording,High Definition video distribution,High Definition camcoder archiving,mass data storage,professional storage and digital asset management.