There seems to be some confusion about Blu-ray Discs and the newer 4k Ultra HD Blu-ray format. Quite simply, the two are not the same. However, the two formats are often packaged together in combo editions. That way, if you have a second Blu-ray player somewhere in the house, or haven’t upgraded to a 4k Blu-ray player yet, you’ll get both formats. Blu-ray Disc combo editions typically have DVDs that can be played on laptops, car entertainment systems, and older DVD players. Let’s take a look at some differences to help you understand.
Video resolution on Blu-ray discs is 1,080 x 1,920 (even though source material may not be that high). Color range goes up to 8-bits. Audio formats can range from Dolby Digital 5.1 to higher-quality Dolby TrueHD 7.1, Dolby Atmos, DTS-HD Master Audio 7.1, and DTS:X. Blu-ray Discs can be played on Blu-ray players and 4k Ultra HD Blu-ray players.
4k Ultra HD Blu-ray
4k Ultra HD Blu-ray discs have a video resolution of 3,840 x 2160 and can support HDR in Dolby Vision or HDR10/HDR10+. HDR adds more color depth (up to 10 bits) but can only be viewed on 4k TVs that support HDR. Audio formats can range from Dolby Digital 5.1 to higher-quality Dolby TrueHD 7.1, Dolby Atmos, DTS-HD Master Audio 7.1, and DTS:X. 4k Ultra HD Blu-ray discs are only playable on 4k Blu-ray players.
We hope that helps! If you have any further questions please post in the comments below and we will do our best to answer.