Freud saw the preconscious as characterised by reality-testing, recallable memories, and (above all) links to word-presentations—the key distinction from the contents of the unconscious. In Chapter 2 of his book, The Ego and the ID, Freud explains that the real difference between an unconscious idea and a preconscious idea is that unconscious ideas are based on unknown material, whereas preconscious ideas are usually brought into consciousness via connections with word-presentations.
Freud's theory posits that the preconscious is characterized by reality-testing, accessible memories, and most notably, connections to verbal presentations—the key distinction from the contents of the unconscious. In Chapter 2 of his book, The Ego and the ID, Freud clarifies that the primary difference between an unconscious idea and a preconscious idea lies in the fact that unconscious ideas are rooted in unknown material, whereas preconscious ideas are usually brought into consciousness via associations with verbal presentations.