The Johari Window model is a tool for self-awareness, personal development, and understanding relationships. It was developed in the 1950s by psychologists Joseph Luft and Harry Ingham. The model represents what is known and unknown about a person by themselves and others. There are four "panes" or areas: open area (known to self and others), blind area (known to others but not self), hidden area (known to self but not others), and unknown area (unknown to self and others). The goal is to increase the open area through feedback, disclosure, and discovery to improve communication and relationships. It can be applied to individuals and teams to understand dynamics and facilitate development.