The word demography comes from two ancient Greek words, demos, meaning "the people," and graphy, meaning "writing about or recording something" — so literally demography means "writing about the people." Like many branches of the sciences, demography began in the 19th century, when the general craze for cataloging .
Demography is defined as a study of human population including its size, distribution, composition and the factors that determine changes in its size, distribution and composition..
Having measured these components, demographers have at their disposal tools—both more and less sophisticated—to enable them to predict the development of these components in time and space and thereby predict the movements and developments of populations
In that sense, demography is a victim to some extent of its own terminology
Life expectancy at birth to the layman means exactly that—life expectancy at birth
There is no understanding of what this demographic measure really is, and in truth, it is not the fault of the layman
