Answer:
Population change is simply the change in the number of people in a specified area during a specific time period. Demographics (or demography) is the study of population statistics, their variation and its causes. ... All of these statistics are investigated by censuses and surveys conducted over a period of time.
— https://en.m.wikipedia.org/wiki/Population_change#:~:text=Population%20change%20is%20simply%20the,their%20variation%20and%20its%20causes.&text=All%20of%20these%20statistics%20are,over%20a%20period%20of%20time.
