Blu-ray is a type of disc that is used to store video and audio information. Blu-ray discs look like regular DVDs, but are much bigger, meaning they can store much more information. When you put a Blu-ray disc into your DVD player, your DVD player will read the disc and show you the video or audio that is stored on it. Blu-ray discs can also be used with some computers, so you can watch movies or listen to music stored on the disc.