Principle purpose of this article is to explain Basics of Social Science in terms of Demography. Demography is the study of human population- their size, composition and distribution across place- along with the process through population modifications. Births, deaths and migration would be the ‘big three’ of demography, along producing population stability or perhaps change. Here also briefly explain Elements of Demography, Demographic Transition, Migration, Social Mobility, Social Stratification, Ascribed Status and Achieved Status in terms of Demography in society.