Demography is the scientific study of human populations primarily with respect to their size, their structure and their development; it takes into account the quantitative aspects of their general characteristics.
A population’s composition may be described in terms of basic demographic features – age, sex, family and household status – and by features of the population’s social and economic context – language, education, occupation, ethnicity, religion, income and wealth. The distribution of populations can be defined at multiple levels (local, regional, national, global) and with different types of boundaries (political, economic, geographic). Demography is a central component of societal contexts and social change.
Census includes the total process of collecting, compiling, analyzing, evaluating, publishing and disseminating statistical data regarding the population and housing and their geographical location. Population characteristics include demographic, social and economic data and are provided as of a particular date (reference period).
Population censuses typically use one of two approaches:
- De facto – meaning enumeration of individuals as of where they are found in the census, regardless of where they normally reside.
- De jure - meaning enumeration of individuals as of where they usually reside, regardless of where they are on census day.
Importance of census:
- Information on population size and its distributions by various characteristics describe the socio-economic and demographic circumstances of a country/area which are essential to formulate and implement policies and development programs.
- Population census is the principle source of such data which serves as bench mark to develop policies/programs for the welfare of the country and its population.
- Availability of information at the lowest level of Admin units is also valuable for the management and evaluation of development programs like literacy and education, employment and manpower etc.