What is VESA Certified DisplayHDR 400?
For example VESA DisplayHDR 400 is for screens which can reach 400 cd/m2 peak brightness, HDR 600 for those that can reach 600 cd/m2 and so on. Peak brightness is pretty important for an HDR display, as you need to be able to produce brighter highlights and more lifelike bright images to improve the overall experience.