Why is Age composition considered as one of the most basic characteristic of population? Explain.

heya, Sapna!
   It is one of the most basic characteristics of a population because :
(1) A person’s age influences his needs.  (2) A person’s age influences his buying habits.
(3) A person’s age influences his capacity to perform.  (4) Age groups are notable determinants of the population’s social and economic structure. hope this helps!thumbs up plz!