Sigmund Freud, the founder of psychodynamic approach to psychology which looks at the unconscious drives instead of conscious ones to explain human behavior. According to him there are three aspects of mind that influence a person’s personality – id, ego and superego.

Id is the part of subconscious mind which seeks pleasure and is driven by most primal instincts of humankind. In nature it is impulsive and yearns for immediate satisfaction. Id does not have a moral compass. It wants what it wants, not what it can have. 

Ego, on the other hand, is the realistic aspect of mind which tries to seek a balance between the demands of id and realities of the world. Ego does not differentiate between right and wrong. It differentiates between possibilities and fantasies.

Superego is the conscience of mind. It follows the norms of the society and reins in impulses which are contrary to those norms. It is the check on behavior of a person allowing him to adjust through the morality of the society.