Demography's the statistical study of all populations. It can be a very general science that can be applied to any kind of dynamic population, that's, one that changes over time or space (see population dynamics). It encompasses the study of the size, structure and distribution of populations, and spatial and/or temporal changes in them in response to birth, migration, aging and death. Demography's that branch of social science,which deals with the study of size,structure and distribution of p… (More on Demography)