Demography is the study of human population and the statistics related to it. It is a branch of sociology. Things like age, income, race, migration, and religious beliefs are all examples of things that may be studied under demography. Through analyzing patterns and figures, demography aims to understand the behavior of humans all around the world. Demography can help countries plan for things such as a quickly-growing population, a quickly-aging population, and a population where men or women outnumber one another.