Q.Which country is most populated in the world ?

The demographic transition model describes how a country's birth rate and death rate change as it develops, moving the population through stages from high growth to eventual low or stable growth. It is the framework for grouping the demographic features of India, China and Pakistan and for understanding why their populations look so different today.

In the early stage, both birth and death rates are high, so the population grows slowly and fertility is very high. As development brings better food, sanitation and healthcare, death rates fall while birth rates stay high — this is the explosive-growth stage, marked by a large and rapidly growing population and high density. As education, urbanisation, income and family planning spread, birth rates finally fall too, fertility drops, and growth slows toward stability, typically accompanied by high urbanisation and, eventually, an ageing population. …