Blu-ray disc is the third generation optical disc format that was developed by the Blu-ray Disc Association to offer more storage than DVDs. Blu-ray discs use a blue-violet laser instead of red to allow for smaller pits and a higher density that can hold up to 50GB of data. They come in different formats for video, recording, and data storage and use various technologies like a hard coating and secure encryption to be durable and protect against piracy.