The Self in Jungian psychology is one of the Jungian archetypes, signifying the unification of consciousness and unconsciousness in a person, and representing the psyche as a whole. The Self, according to Jung, is realised as the product of individuation, which in his view is the process of integrating one's personality.
For Jung, the Self is symbolised by the circle (especially when divided in four quadrants), the square, or the mandala.
What distinguishes Jungian psychology is the idea that there are two centers of the personality. The ego is the center of consciousness, whereas the Self is the center of the total personality, which includes consciousness, the unconscious, and the ego. The Self is both the whole and the center. While the ego is a self-contained little circle off the center contained within the whole, the Self can be understood as the greater circle.
Jung considered that from birth every individual has an original sense of wholeness - of the Self - but that with development a separate ego-consciousness crystallizes out of the original feeling of unity. This process of ego-differentiation provides the task of the first half of one's life-course, though Jungians also saw psychic health as depending on a periodic return to the sense of Self, something facilitated by the use of myths, initiation ceremonies, and rites of passage.
Once ego-differentiation had been successfully achieved, and the individual securely anchored in the external world, Jung considered that a new task then arose for the second half of life - a return to, and conscious rediscovery of, the Self: individuation.