HEDT, or High End Desktop, is an acronym originally coined by Intel to refer to their high end consumer desktop PC platforms designed for enthusiasts, gamers, and content creators. Today, both Intel and AMD refer to their high end consumer desktop PC platforms as HEDT.
Some of Intel’s HEDT platforms include X79 (Sandy Bridge-E, Ivy Bridge-E), X99 (Haswell-E, Broadwell-E), and X299 (Skylake-X, Kaby Lake-X). AMD’s HEDT platforms include X399 (Threadripper).