Blu-ray disc is the next generation optical disc format that can hold 25/50GB of data, over 5 times the storage of DVDs. It uses a blue-violet laser with a wavelength of 405nm to read data stored in smaller pits than DVDs. Blu-ray discs come in different formats for video, data storage, and HDTV recording, and can hold multiple hours of HD video on a single or double layer disc. The technology provides improved durability, security, and faster data access compared to DVDs.