Population histograms are graphical representations that show the age and sex composition of a population. They are also known as population pyramids because of their shape. These histograms help in understanding population growth, economic development, birth rate, death rate, and life expectancy. Two important types of population histograms are expansive population histograms and stationary population histograms. They represent different stages of demographic development and reflect the relationship between human beings and their environment. An expansive population histogram is characterized by a broad base and a narrow top. This shape indicates a high birth rate and a rapidly growing population. A large number of children and young people are present in the population, while the number of elderly people is comparatively low. Such histograms are commonly found in developing countries where medical facilities, education, and economic conditions are still improving. Countries in parts of Asia, Africa, and Latin America often show expansive population structures. In an expansive histogram, the broad base shows that many children are being born every year. The narrow upper portion indicates that fewer people survive to old age because of poor healthcare, malnutrition, diseases, and low living standards. Rapid population growth puts pressure on natural resources such as land, water, forests,