Jung contends that the personal unconscious consists of more or less superficial layers, but that it rests upon a deeper layer, which does not derive from personal experience; it is not a personal acquisition but an inborn quality. He calls the deeper layer the collective unconscious and explains that it is universal; it contains images and modes of behavior that are more or less similar everywhere, in all individuals.
Jung describes the collective unconscious as a common psychic substrate of a suprapersonal nature which is present in every human being. As opposed to the personal unconscious which consists mostly of complexes, the collective unconscious contains archetypes. The concept of the archetype, which is closely associated with the idea of the collective unconscious, refers to the existence of definite forms in the psyche which appears to be present always and everywhere.