Using the same 120mm physical form factor as CD and DVD media, storage capacities of Blu-ray media are 25GB per disc (single-layer), 50GB per disc (dual-layer) and 100GB per disc (quad-layer) on a single-sided medium, and are 100% backward read/write compatible with all known CD and DVD formats.
In addition to the capacity increases offered by Blu-ray technology, a significant advance over CD and DVD media is the hard protective coating which protects the media surface against scratches, dust particles, and other contaminants, ultimately providing much greater longevity over CD and DVD. Likewise, Blu-ray media is liquid repellant and offers greater protection against extreme temperature and humidity, when compared to CD and DVD media.
For data archival applications requiring protection against accidental or deliberate modification or destruction of data, Blu-ray media is available in a Write-Once format (BD-R), which stores data in a non-rewritable non-erasable format to meet regulatory requirements for SEC 17a-4, HIPAA, and Sarbanes-Oxley, to name a few.
For data storage applications that do not require write-once properties, Blu-ray media is available in a re-writeable format. This format, known as BD-RE, allows deletions of data and the ability to re-claim storage capacity on the disc.
When choosing Blu-ray as a data storage/archive medium, automated libraries offer capacities that range from 5TB to 175TB of archival storage in a single library, and can be hosted by any Windows, UNIX, or Linux operating system.
Blu-ray libraries also offer the ability to provide network access to collections of CD and DVD discs such as catalogues, encyclopedias, research databases, and software installation discs within the same library as storage and archival media.