The Ultra HD native means that the video content is encoded in resolution 3840x2160 pixels.
The 4K native means that the video content is encoded in resolution 4096x2160 pixels (professional resolution).
The Ultra HD upscaling means that the video content is encoded in resolution 1920x1080 or 1280x720 and scaled to 3840x2160 pixels to be better displayed on Ultra HD TV.
The Ultra HD video content advantages vs Blu-ray contents:
- 3840x2160 instead of 1920x1080 (4 times resolution)
- HEVC instead of AVC video codec compression (5 times better encoding)
Extra benefits of Ultra HD Blu-ray contents vs Blu-ray contents:
- 10-Bit video grading instead of 8-Bit (4096 levels of primary colors instead of 256)
- Larger gamut for better color saturations and more natural colors (REC-2020 instead of REC-709)
- Higher average video bitrate (100 Mbps instead of 40 Mbps)
- Higher dynamic range (HDR)