Threadripper is AMDs enthusiast CPU lineup that is build to go against Intels X series lineup in the i7X and i9X etc. These are for people that do stuff like rendering and CAD and MAYA work and need a lot of threads for their Applications. Threadripper only goes as high as 16 cores while AMD Epyc is a 32 Core Behemoth and also has a Dual Socket motherboard where you can slap on 2 of the highest end Epyc CPUs and have a 64 core 128 thread mamajamma. Those are Server CPUs and have lower clocks.