A:Answer Each series builds on each other. Both of these series are 4K UHD, have HDR support, and have a Roku operating system. The new 5-Series feature Dolby Vision support, wide color gamut, auto-game mode, an edge-to-edge glass display, QLED technology, CCZ, eARC, etc. You can also visit www.tcl.com/us/en/products/home-theater/5-series and scroll down to "Compare All Models" to see all models compared. Hope this helps! Thank you, TCL Customer Support