The three components of population change are:
1. Birth rate: Number of live births per thousand in a year per thousand is called Birth Rate. In less developing countries, the birth rate is generally high that can be controlled by proper family planning. Birth rate increases the density of population.
2. Death Rate: Number of deaths in a year per thousand is called date rate. It is not too high normally but becomes quite high during some epidemic or natural disasters or food scarcity. The death rate is controlled by proper Medicare. It decreases the density of the population.
3. Migration: Migration is process in which people move from one place to another place. The push and pull factors influence migration. It is a spontaneous effort to achieve a better balance between population and resources.