Rapport is establishing a relationship based on confidence and influence through empathy and sympathy. It involves mirroring the other person's posture, words, and metaphors to build understanding. There are four levels of rapport: presence and partnership, posture and words, questions and patience, and understanding psychology and personality types using the PEMS model. Carl Jung's work on psychological archetypes and the Myers-Briggs Type Indicator influenced the PEMS model, which categorizes people as practical, emotional, mental, or spiritual based on their preferred psychological functions. Understanding these personality differences is important for building rapport.