Blu-ray is the name of a new optical disc format. The format was developed to enable recording, rewriting, and playback of high-definition video, as well as storing large amounts of data.
The format offers more than five times the storage capacity of traditional DVDs. While current optical disc technologies such as DVDs rely on a red laser to read and write data, the new format uses a blue-violet laser instead, hence the name Blu-ray.
The benefit of using a blue-violet laser is that it has a shorter wavelength than a red laser. This makes it possible to focus the laser spot with even greater precision.
As a result, data can be packed more tightly, and stored in less space. Therefore, it’s possible to fit more data on a Blu-ray disc, even though it’s the same size as a CD or DVD.