The word 'Demography' is derived from the two Greek words 'Demos' and 'Graphy'. The word Demos means people and Graphy mean to write and to study.
Social Demography explains the issues of population studies by relating with the social and economic aspects.
In primary sources, the data are collected directly from the field observation or households by using various data collection tools like questionnaire, observation, interview, etc.
Census simply means the counting of people of a certain area at a certain time.
The modern and orderly census was first started in New France and Acadia in 1665 AD.
In Nepal, the first census was conducted in 1911 AD.
The Census is conducted by most of the countries of the world under the guideline of UN.