Jung concluded that Freud had developed an extroverted theory of personality and Adler an introverted theory. On the basis of this he determined that people had a preference for one of these attitudes and could be classified into introverts or extroverts. Jung defined type as how psychic energy flows naturally but believed that just continually using the most preferred orientation could lead to rigid and dysfunctional behaviour. In fact there is no such thing as pure type and a psychologically healthy person is able to draw on all functions when appropriate.
Personality is viewed as a model of processing information.
We perceive or take in information through sensation or intuition and then evaluate or judge what to do with the information through feeling or thinking. A person who has a preference for sensing is more likely to take in information as it exists than an intuitive person who often makes meaningful connections with the same information. A feeling type will evaluate information in terms of personal or social values whereas a thinking type will evaluate the same information by using objective or logical criteria. Extroverting and introverting refers to internal or external world orientations and not necessarily whether a person is sociable or shy. Thus an extroverted feeling type is likely to base decisions on personal or social values that please or impress others whereas as an introverted feeling type is more likely to base decisions on internal values which may not be shared or communicated to others.