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The name Blu-ray Disc is derived from the blue-violet laser used to read and write this type of disc. Because of its shorter wavelength (405 nm), substantially more data can be stored on a Blu-ray Disc than on the DVD format, which uses a red (650 nm) laser. A single-layer Blu-ray Disc can store 25 gigabytes (GB), over five times the capacity of a single layer DVD at 4.7 GB. A dual-layer Blu-ray Disc can store 50 GB, almost six times the capacity of a dual layer DVD at 8.5 GB.

The Blu-ray standard is currently in a format war with its rival HD DVD, to determine which of the two formats will become the leading carrier for high-definition content to consumers.