ARCHIVED: What is Blu-ray?

This content has been archived, and is no longer maintained by Indiana University. Information here may no longer be accurate, and links may no longer be available or reliable.

Blu-ray discs are a form of optical storage media with the same size and shape as a CD or DVD. Built for high capacity, Blu-ray discs are intended to store high-definition video and large amounts of data. The name of the technology stems from the shorter wavelength used by the laser which reads information from the disc. Instead of using a red laser like a CD or DVD player, Blu-ray players use a blue-violet laser.

The primary advantages Blu-ray discs have over previous optical formats are vastly larger capacity (50GB for a dual layer Blu-ray disc vs. 8.5GB for a dual layer DVD) and much higher reading speed. The fastest Blu-ray players read at 432Mbps, compared to 168.75Mbps for the fastest DVD players. This higher speed is essential for playing back high-definition video, where the amount of data required in real time exceeds the capabilities of most DVD players.

Every version of Sony's PlayStation 3 video game console is also a Blu-ray player, and many new computers are available with Blu-ray drives as a factory option. Blu-ray drives are available as stand-alone upgrades for existing computers; however, playback of high-definition content requires an HD-capable graphics card. Check with the manufacturer of the drive to make sure your computer meets the system requirements before you purchase it.

For more on Blu-ray technology and products, see the Blu-ray Disc Association web page.