Introduction to population change

The size of population of any country does not remain Constanta population always clangers. by population. decrease in population size in different time periods. you have already read that since 1940AD the population size of Nepal has been tremendously increasing. birth death and migration are the main factors of population change.birth and death are natural factors of population change. birth increases the population, death decreases and migration can bath increase and decreases it. In migration increases the population but out migration decreases it. In facto, these three factors change the total population.