From Wikipedia, for what it’s worth:A ghoul is a cannibalistic monster that feeds on human corpses and living human flesh, abducts young children to eat, lures unwary people into abandoned places, often classified as undead. The creatures usually dwells in graveyards and cemeteries. The oldest surviving literature that mention ghouls is likely One Thousand and One Nights1. The term was first attested to in English in 1786, in William Beckford’s Orientalist novel Vathek,2 which describes the ghūl of Arabian folklore.Zombies are fictional undead creatures regularly encountered in horror and fantasy themed works. They are typically depicted as mindless, reanimated corpses with a hunger for human flesh, and particularly for human brains in some depictions. Although they share their name and some superficial similarities with the zombie from Haitian Vodun, their links to such folklore are unclear1 and many consider George A. Romero’s seminal film The Night of the Living Dead to be the progenitor of these creatures.23 Flesh-eating zombies have a complex literary heritage, with antecedents ranging from Richard Matheson and H. P. Lovecraft to Mary Shelley’s Frankenstein, all drawing on European folklore of the flesh-hungry undead. The zombie apocalypse, the civilized world brought low by a global zombie infestation, has become a staple of modern popular art. By 2011 the influence of zombies in popular consciousness had reached far enough that the United States government’s Center for Disease Control used the idea as a theme to promote disaster preparedness.4So it seems all zombies are ghouls, but not all ghouls are zombies.