They are different things, terror and fear. The first one is immediate, it takes over all the senses at once, it turns them into uncontrolled despair and panic. The second is slower, but, perhaps, more cruel. The sensation is created gradually and grows in silence as it takes over everything. It continues to grow like a great shadow, and when its victims become aware of it, it is already too late. Anxiety becomes intolerable and the voice becomes a scream that cannot get out, as if it is chained in the guts of the throat as it struggles to escape.