Birth rate and death rate are the important components of population change.
Birth rate is the number of live births in a year per thousand population.
Death rate is the number of deaths in a year per thousand population.
Population growth depends upon birth rate and death rate in a year.
Population growth occurs not only by increasing birth rate but also because of decreasing death rate.
When birth rate is more than death rate, population increases.
When birth rate is less than death rate, population decreases.
If both, birth rate and death rate is same then population is said to remain stable. However, the birth rate and death rate being same is only a hypothetical situation.