Maslow's hierarchy of needs is an incentive theory in psychology, including a five-level model of human needs, which is usually described as the hierarchy within the pyramid.

From the lowest level to the highest level, the needs are: physiology (food and clothing), safety (job security), social needs (friendship), respect and self-realization. This five-stage model can be divided into insufficient demand and increased demand. The first four levels are usually called defect demand (D demand), and the highest level is called growth demand (B demand).