(1) Population change is the change that may result due to migration ,deathrate,birthrate and changes in age composition and sex ratio .
(2)even when there is no population growth ,there may be a population change.
(3) internal migration brings about a change in population of a country .
(4) in a given population , if there is a change in the sex ratio ,it will be considered a population change
# Birth rate : it is the no.of live births per 1000 Pearson's.
#Death rate: it is the no.of deaths per 1000 Pearson's
# Migration: it is divided into two parts - internal migration
- external migration
* internal migration: moving within the country, this doesn't change the size of the country but composition and distribution of population gets changed.
* external migration: moving from one country to other, this changes the size of the population.