Relier Pairs Measuring populationsVersion en ligne Now you have to relate the terms with its definition. par Laura Jiménez Ruiz 1 Immigrant 2 Absolute population 3 Natural increase 4 Emigrant 5 Population density 6 Actual increase The difference between the number of births and the number of deaths. A person who moves away from an area. The total number of people living in an area. Includes the natural increase, the immigrants arriving and emigrants leaving. A person who moves into an area. The average number of people who live in each square kilometre of land.