Blu-ray

Blu-ray is an optical disc format that was developed to enable recording, rewriting and playback of high-definition video, called HD. A Blu Ray disc looks like a DVD or CD but it can hold almost six times the capacity of a double-dual layer DVD and more than 10 times the capacity of a single-layer.

Blu-ray uses blue-violet laser light to read and write data instead of red which is used by DVD. It's liked because it can hold substantially more data than the DVD format.