Answer:
It is an approach to psychology (initiated by Rogers, Maslow) that focuses on a person as a wholeness, including body, mind, emotions (and 'soul' - see the latest works of Rogers).
The main idea is that each person has a immanent, natural drive to the self-development and the main goal of psychology/psychologer is to create the best, appropriate environment for development. Free of judgement, empathetic, open-minded. If we create this kind of environment EACH person will develop their full potential.