Population refer to the number of people living in a particular area. The study of a population in terms of statistics pertaining to its size, composition and other perameters such as birth rate, death rate, growth rate as also ageing is known as demography. The size of a country's population influence its social and economic condition. Population density is a perameter derived by dividing the population figure of a place by its area. A place with smaller area would have a higher population density than one with a larger area if the population two places are equal.