As per usual TV manufacturers have a new format or buzz term to throw around. However HDR (High Dynamic Range) is probably the most useful advancement in Television since HDTV went mainstream.
So what exactly is HDR? Its basically a new technique of lighting screen images in certain parts of the display. This is
not currently achievable through normal display or photography technology.
Why and what does this mean for my TV? Well, it means that a TV that has HDR capabilities can more accurately reproduce brightness and color to the parts of the screen that need it. Again similar to the way 4K is limited in content so is HDR. As of now its basically available through streaming services like Netflix and Amazon . However Ultra HD Blue Rays are capable of transmitting these images. Again content is still limited but, HDR seems to display better picture quality than that of 4K alone. If one were to see a 4K TV with obviously more pixels than a 1080 HDR. Most people will choose HDR with a lesser pixel display than a non HDR 4K TV.
It's not to say that 4K with appropriate content doesn't give outstanding details in picture quality. It far exceeds 1080. However the more life like colors and brightness HDR is capable of
give a truer more life like image with some of the most accurate colors and brightness available thus far.