Blu-ray Disc is an optical disc storage media format used for high-definition video and data storage having the same dimensions as a standard DVD or CD. The blue-violet laser is used to read and write this type of disc, hence the name. Blue laser rays of 405 nanometer is used for Blu-ray Disc, while red laser rays of 650nm are used DVD format. Because of this, a dual layer Blu-ray Disc can store 50 GB, almost six times the capacity of a dual-layer DVD.
Blu-ray was developed by the Blu-ray Disc Association, a group of companies representing consumer electronics, computer hardware, and motion picture production. Currently more than 450 Blu-ray Disc titles have been released in the United States, and more than 250 in Japan. The Blu-ray format was promoted by Sony.