Demographic Components

Population change results from the interaction of demographic components: birth, death and migration. Therefore, demography deals with the detailed study of the three components. With the measurement of such components, various aspects of the population are analyzed and interpreted. It helps to plan and implement various development activities. Birth, death and migration are called demographic component, as well as the determining elements of population change because they affect the situation of the population. Therefore, the size of the population depends mainly upon birth, death and migration.

Fertility

Birth is an important component mainly related to fertility in the study of population education. Fertility deals with the birth. The population growth of a place/country depends upon fertility because the country with high level of fertility has a rapid growth of population. Fertility refers to the reproductive function. It is the ability to bear offspring. It is the production of live birth which starts when a woman gives the first birth. Its period is generally 15-49 years of age. Likewise, fecundity is the physical capacity to participate in reproduction. It starts with the regulation of monthly menstrual cycle. Fertility results in the birth. It is measured by the actual number of births.

Mortality

According to WHO, "Death is the permanent disappearance of all evidence of life at any time after birth has taken place." It is a natural process. The process of birth and death goes on incessantly. People die at different ages for different reasons. People die of different diseases and in several accidents. This is a perpetual process. This process causes the decline in population.

Migration

Migration means the movements of people from place to place. The movement of people inside the country is called national migration like Bhaktapur to Kathmandu. And the movement of people from one country to another is called international migration like Nepal to China.

The people who shift from the original place are called out-migrants and those people who live in their destination called in-migrants. In the same way, people who shift from one country to another are called emigrants for departure and immigrants for the destination. The difference in the number of people due to immigration and emigration in a country is called gross migration.