The id ego and superego are the components of Freud's psychic structural model:

• The id is the primal form of the psyche
• The ego is the conscious norm.
• The superego is the higher self expressed as a functional entity.

Interestingly, this is also a pretty close match to current evolutionary theories of brain development in humans. Freud's structure is a practical approach to describing the states of psychological activity as processes, with the id as the raw material, the ego as the organized, active and reactive psyche, and the superego as the intellect combined with the rational and emotional functions. It will be noted that these descriptors includes a natural progression of development.