The document discusses population and demography, providing definitions and theories. It defines population as people living in a geographic area, and demography as the organized study of a population's size, composition, and changes. Several population theories are described, including Professor Car-Saunders' theory of an optimum population size based on resources and needs, and Professor Thompson's theory of population passing through static, growing, and then again static stages with development. Issues of overpopulation in Pakistan are also summarized, with high birth rates compared to decreasing death rates leading to problems of shortage, unemployment, and increased crime. Causes of overpopulation in Pakistan include the desire for male children, poverty, lack of family planning awareness, and early/polygam