Explanation:

Maslow's hierarchy of needs is a motivational theory in psychology comprising a five-tier model of human needs, often depicted as hierarchical levels within a pyramid. From the bottom of the hierarchy upwards, the needs are: physiological (food and clothing), safety (job security), love and belonging needs (friendship), esteem, and self-actualization. Needs lower down in the hierarchy must be satisfied before individuals can attend to needs higher up. 

This five-stage model can be divided into deficiency needs and growth needs. The first four levels are often referred to as deficiency needs (D-needs), and the top level is known as growth or being needs (B-needs).Deficiency needs arise due to deprivation and are said to motivate people when they are unmet. Also, the motivation to fulfill such needs will become stronger the longer the duration they are denied. For example, the longer a person goes without food, the more hungry they will become.