Transference is one of the most important concepts in psychoanalysis. This concept refers to the process by which the analysand (i.e., patient) relates to the analyst (i.e., therapist) as if the analyst were someone from the analysand's past.
The transference experience grows over the course of an analysis. Over time the analyst will work to interpret the transference which will assist the analysand in understanding how he or she colors experiences based on past internal representations and how such representations constrain experience of self and other.
Transference is not limited to the analytic situation, but more or less occurs in all relationships in our lives. However, most analyses are designed to encourage the development of the transference. For example, the relatively silent analyst, the limited face to face contact, the 3- to 5x/week sessions, all contribute to a space that deepens a transference.
Of note, and this will take a node in itself, psychopathology can be described on a continuum from the psychotic level of ego organization to maturity. Correspondingly, the nature of the transference (and of many aspects of psychological experience, i.e., defenses, identity, etc.) differs across levels of ego organization. Consider an overly simplified example of a mother transference. To the person who is in a psychotic state, the therapist IS the mother; however, to the neurotic, the therapist is just LIKE the mother. The difference between these two experiences can be explained by a concept called potential space which was developed by D. W. Winnicott and elaborated on by David Ogden. A potential space node will soon follow.