Maslow's Need Hierarchy Theory outlines 5 levels of human needs: 1) Physiological needs like food and shelter, 2) Safety and security needs, 3) Social needs including belongingness and friendship, 4) Esteem needs involving respect and status, and 5) Self-actualization needs relating to achieving one's full potential. Physiological needs are the most basic and must be met before progressing up the hierarchy to higher level needs of safety, social belonging, esteem, and self-actualization.