The distinction between terror and horror was first characterized by the Gothic writer Ann Radcliffe (1764–1823). Terror is characterized by "obscurity" or indeterminacy in its treatment of potentially horrible events; it is this indeterminacy which leads to the sublime. She says in the essay that it "expands the soul and awakens the faculties to a high degree of life". Horror, in contrast, "freezes and nearly annihilates them" with its unambiguous displays of atrocity.

She goes on: "I apprehend that neither Shakespeare nor Milton by their fictions, nor Mr Burke by his reasoning, anywhere looked to positive horror as a source of the sublime, though they all agree that terror is a very high one; and where lies the great difference between horror and terror, but in uncertainty and obscurity, that accompany the first, respecting the dreader evil. "According to Devendra Varma in The Gothic Flame (1966): The difference between Terror and Horror is the difference between awful apprehension and sickening realization: between the smell of death and stumbling against a corpse. Horror is also a genre of film and fiction that relies on horrifying images or situations to tell stories and prompt reactions in their audiences. In these films the moment of horrifying revelation is usually preceded by a terrifying build up, often using the medium of scary music.”