Population Aging: Population aging refers to an increase in the proportion of older individuals within a population due to declining birth rates and increasing life expectancies.
Demographic Shifts: Demographic shifts represent changes in the composition and characteristics of populations over time due to factors such as declining birth rates.
Total Fertility Rate (TFR): TFR measures the average number of children that would be born alive to each woman if she were to pass through her entire childbearing years conforming with age-specific fertility rates.