DVDs and Blu-rays are built practically the same, but given that Blu-ray players can play DVDs just fine, it seems strange that Blu-Rays themselves are unable to work on DVD players in the same way. The reason for this all has to do with the advanced way in which Blu-rays store information.
In order to support high-definition video modes such as 720p or 1080p, Blu-rays come equipped with specially designed pits that are far smaller than those of a DVD. To scan its dense storage of video and audio information, Blu-rays require blue laser technology, which is where the format’s name originates. DVDs, on the other hand, utilize red lasers to scan their content, which can be read by either regular DVD or Blu-ray players. However, your average DVD player is unable to produce the blue lasers needed to activate a Blu-ray disc, resulting in their incompatibility. Thankfully, many manufacturers produce home media bundle packages that include both DVD and Blu-ray versions of the movie or show, giving buyers more options.
It’s worth noting that 4K and Ultra HD Blu-rays will not play on standard Blu-ray players. Similar to the distinction between Blu-rays and DVDs, Ultra HD stores even more information, with as much as 100GB needed to support their higher quality formats. At the end of the day, it’s worth obtaining a 4K or Ultra HD Blu-ray player so there’s no worry about playing whatever physical format has your heart.
