UHD Blu-ray usually means a 4K Blu-ray source, often the upstream source for premium 2160p releases. It is more likely to carry HDR10, Dolby Vision, TrueHD or DTS-HD than ordinary 1080p Blu-ray. The tag says the source can be strong, but it does not automatically make the specific file the best version. Compare Remux or BDRip, codec, size and audio together.