Meaning

noun the people who inhabit a territory or state

noun a group of organisms of the same species inhabiting a given area

noun (statistics) the entire aggregation of items from which samples can be drawn

originBorrowed from Late Latin populatio (“a people, multitude”), as if a noun of action from Classical Latin populus, equivalent to populate + -ion. Doublet of poblacion.

Etymology from Wiktionary, CC BY-SA 3.0