What Is A Blu-Ray Disc?

Date First Published: 17th March 2024

Topic: Computer Systems

Subtopic: Computer Hardware

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn about what a Blu-ray disc in this article.

Blu-ray is an optical disc data storage format designed to supersede the DVD format. It is the same physical size as a CD or DVD, but offers more than five times the storage capacity of DVDs and the ability to store high-definition video and data.

Unlike CDs and DVDs, which use a red laser to read and write data, a Blu-ray disk uses a blue laser, which increases data transfer rates and capabilities. This is because the laser is narrower with a shorter wavelength of 405 nm, compared to 650 nm for DVDs and 780 nm for CDs.

The name "Blu-ray" comes from the blue-violet laser the Blu-ray drive uses to read data. Like other optical disc formats, Blu-ray discs contain data encoded as a series of pits and bumps in reflective material on the underside of the disc. This is read by a laser in the disc drive and decoded.

Features Of Blu-Ray Discs

The key features of Blu-Ray discs include:

• 36-48 Mb/s average data transfer rate.
• Compatibility with full MPEG2 encoding, MPEG4 AVC, and VC1.
• Support for audio output from players with analogue, digital optical, coaxial, and HDMI connectivity.
• Support for networking and internet capabilities.
• Support for next-generation sound formats, such as Dolby Digital Plus.
• Backwards compatibility support - Blu-ray is backwards compatible with DVDs and CDs. This means that Blu-ray disc players can play DVDs and CDs.

Storage Capacity

The storage capacity of a Blu-ray disc varies, depending on the number of sides and layers. Double-layer and double-sided Blu-ray discs can store more data than single-sided and single-layer discs.

The Blu-ray disc can hold as much as 25 GB on a single side, giving it more than five times the storage capacity. A dual-layer Blu-ray disc holds up to 50 GB, which is as much as ten DVDs. Due to the higher storage capacity, it is more suitable for storing high-definition films on disc.

History

Blu-ray was invented and developed in 2005 and released worldwide on 20th June 2006. It was jointly developed by a group of personal computer and consumer electronics companies called the Blu-ray Disc Association.

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