While almost all new 4K televisions have support for HDR, not all of them have HDR10 or Dolby Vision support. HDR is just a fancy way of saying the TV is capable of boosting color, contrast, and image-sharpening algorithms to produce a better picture. It isn't strictly necessary to buy a TV that has these features.Unless you're the world's premier movie expert and can spot a dead pixel at 20 paces, chances are you won't notice much of a difference anyway. However, if you want to ensure that your TV can handle image processing for several years, it's worth springing for a model with HDR10 or Dolby Vision. They are newer, more powerful technologies that can future-proof your home theater to some degree.