Short answers, pulled from the story.
The blue laser diode was invented in 1996 and fundamentally changed the trajectory of optical media by allowing information to be stored at a density five times greater than previous formats. This breakthrough operating at a wavelength of 405 nanometers enabled the creation of the Blu-ray Disc format that would eventually supersede the DVD.
A single layer of Blu-ray Disc could hold 25 gigabytes of data compared to the 4.7 gigabytes of a standard DVD. The shorter wavelength allowed the laser to focus on a smaller spot size reducing the pit size from 400 nanometers to 150 nanometers and the track pitch from 740 nanometers to 320 nanometers.
The format war officially began when the first consumer Blu-ray player the Sony BDZ-S77 was released in Japan on the 10th of April 2003. The HD DVD format was championed by Toshiba and the DVD Forum which was initially split over whether to develop the more expensive blue laser technology.
On the 28th of June 2007 20th Century Fox cited the adoption of the BD+ anticopying system as key to their decision to support the Blu-ray Disc format. The real turning point came on the 4th of January 2008 when Warner Bros announced that it would release only in Blu-ray after May 2008.
The specification for an 8K Blu-ray format was completed in 2017 and was exclusive to Japan designed for use by Japanese public broadcasters to broadcast the Tokyo 2020 Olympic Games in 8K resolution. This format represents the latest evolution of the Blu-ray Disc technology following the introduction of Ultra HD Blu-ray in 2015.