Crude Birth Rate:The crude birth rate is the number of live births per 1,000 population in a given year, providing a measure of the fertility level of a population.
Replacement-Level Fertility: The level of fertility at which a population exactly replaces itself from one generation to the next, typically around 2.1 children per woman.
Demographic Transition: The transition from high birth and death rates to low birth and death rates as a country or region develops economically and socially.