If you know very little about psychology, and you have heard of just one psychologist, the chances are that this is Sigmund Freud, the founder of the psychodynamic approach to psychology and psychoanalysis.
If Freud represents your layperson's idea of psychology, then you probably have an image of a patient lying on a couch talking about their deepest and darkest secrets.
In deliberate contrast to behavioral psychology, psychodynamic psychology ignores the trappings of science and instead focuses on trying to get inside the head of individuals in order to make sense of their relationships, experiences and how they see the world.
The psychodynamic approach includes all the theories in psychology that see human functioning based upon the interaction of drives and forces within the person, particularly unconscious, and between the different structures of the personality.
Freud’s psychoanalysis was the original psychodynamic theory, but the psychodynamic approach as a whole includes all theories that were based on his ideas, e.g. Jung (1964), Adler (1927) and Erikson (1950).
The words psychodynamic and psychoanalytic are often confused. Remember that Freud’s theories were psychoanalytic, whereas the term ‘psychodynamic’ refers to both his theories and those of his followers. Freud’s psychoanalysis is both a theory and a therapy.
Sigmund Freud (writing between the 1890s and the 1930s) developed a collection of theories which have formed the basis of the psychodynamic approach to psychology. His theories are clinically derived - i.e. based on what his patients told him during therapy. The psychodynamic therapist would usually be treating the patient for depression or anxiety related disorders.