Abraham Maslow developed a hierarchy of needs theory to explain human motivation. The hierarchy consists of 5 levels of needs - physiological needs, safety needs, love and belongingness needs, esteem needs, and self-actualization needs. Physiological needs are the most basic for survival like food and shelter. Safety needs provide security and well-being. Love and belongingness refers to relationships and social acceptance. Esteem needs involve respect and confidence. Self-actualization is achieving one's full potential. The theory is that lower level needs must be satisfied before progressing to meet higher level needs.