Self-understanding

Theory of personality and its dynamics
He proposed 3systems of the mind – id, ego and superego.
Id. He considered the id to be the original aspect of personality, rooted in the biology of the individual and consist of unconscious sexual and aggressive instincts. Freud linked the id to a “seething cauldron” that contains powerful and primitive urges and desires. Id operates according to the pleasure principle: the aim of these impulses is always immediate and complete discharge and satisfaction. The pleasure principle maintains that people always strive to maximize pleasure and minimize pain. In Freud's psychoanalytic theory of personality, the primary process works to resolve the tension created by the pleasure principle. The pleasure principle is what drives the id and seeks instant gratification of all needs, wants, and desires.
Ego. Adults who act impulsively are called immature and childish; mature conduct demands that we control our impulses in a wide variety of situations. For Freud, this control becomes possible when the ego is differentiated from the id. The ego is the organized aspect of the id, formed to provide realistic direction for the person’s id impulses. The reality principle forces us to consider the risks, requirements, and possible outcomes as we make decisions by temporarily halting the discharge of the id's energy until a suitable time and place. In other words, the ego doesn't try to block an urge, but instead, it works to make certain the desires of the id are met in ways that are safe, realistic, and appropriate. For example, rather than snatching that slice of pizza, the ego will force you to wait until you can buy your own slice, a delay achieved through what is known as the secondary process.
Superego. The superego incorporates the values and morals of society which are learned from one's parents and others. It develops around the age of 3 – 5 years during the phallic stage of psychosexual development. The superego's function is to control the id's impulses, especially those which society forbids, such as sex and aggression. It also has the function of persuading the ego to turn to moralistic goals rather than simply realistic ones and to strive for perfection. The superego operates on the morality principle and motivates us to behave in a socially responsible and acceptable manner.
Instincts: driving forces in personality
In his view, instincts govern our behavior. Instincts have 4 basic characteristics:

1. 
   A source in some bodily deficit;
   
2. 
   An aim – gratification of the need;
   
3. 
   An impetus that propels the person to act;
   
4. 
   An object through which the instinct achieves its aim.
   

As he perceived it, instincts can move from object to object in their attempt to gain maximum gratification(satisfaction). Instincts can even turn inward on the individual, as when a person’s aggressive feelings toward others are turned toward self and result in acts of self-mutilation or even suicide.