Blu-ray Disc is the next-generation optical disc format that was developed to enable recording and playback of high-definition video (HD), as well as storing large amounts of data. A single-layer Blu-ray Disc can hold 25GB, which can be used to record over 2 hours of HDTV. Blu-ray uses a blue-violet laser to read and write data while current optical disc technologies such as DVD use a red laser.