Transference is perhaps not a widely known term. It can be thought of as when a pattern of interacting with an early attachment figure becomes a blueprint for later relationships. Nat Kuhn, in "Intensive Short Term Dynamic Psychotherapy: A Reference" (2014), describes transference as the tendency to "bring aspects of problematic relationships with early attachment figures into therapy". For example, a client with a highly critical mother may tend to feel that the practitioner is being critical towards them and become hostile in response. Working in the transference, which is a key mechanism of change in psychodynamic work, involves focusing on these feelings towards the practitioner, perhaps in the hope of clarifying their origin and thus allowing the client to work through this unresolved emotional content in the context of a secure attachment. It can be differentiated from projection in that it isn't necessarily something you are disowning from within yourself and then projecting onto another, but more the echo of a learned pattern of interacting. There is overlap between the two - there can perhaps be projection in transference, for example. But what is important here is the willingness and the ability to discern between old feelings about past, painful experiences, and new feelings about present experiences. Without this discernment our reactions in the present will never be just our reactions to the present, but instead be forever clouded by echoes from the past.
Thoughts on Therapy and Mental Health