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 6-Series additionally have Dolby Vision Support, wide color gamut, CCZ technology and a brushed metal cabinet. You can also visit www.tclusa.com/products/home-theater/6-series and scroll down to "Compare All Models" to see all models compared. Hope this helps! Thank you, TCL Customer Support
