Blu-ray is a disc format that allows for the viewing of high-definition movies. It is the only format used for high-definition DVDs and DVD players.
Blu-ray technology was developed by a group of electronics manufacturers. Its name comes from the use of a blue-violet laser rather than the red laser used in standard DVD technology. The use of this type of laser allows for a disc to contain a much larger amount of data. A standard DVD holds up to 4.7 gigabytes of data, whereas Blu-ray can hold 25 gigabytes. Dual-layer Blu-rays can hold 50 gigabytes of data. Movies on Blu-ray are estimated to have about six times the image definition of standard DVDs.