Maslow's hierarchy of needs outlines 5 levels of human needs: 1) Physiological needs like food, water, shelter must be met first before moving to higher needs. 2) Safety needs for protection, security and well-being. 3) Love and belonging needs through relationships and acceptance. 4) Esteem needs for inner desires like accomplishment and prestige. 5) Self-actualization needs for reaching one's full potential and satisfaction. The hierarchy suggests lower needs must be satisfied before progressing to meet higher level growth needs.