India has the second largest population in the world.

Explanation:
India is the second most populous country in the world, with a population of over 1.3 billion people. Here are some reasons why India has such a large population:

1. High Birth Rate:
India has a high birth rate, which means that more babies are born each year compared to other countries. This contributes to the overall population growth.

2. Large Youth Population:
India has a large youth population, with a significant proportion of the population being under the age of 25. This youthful demographic contributes to the overall population size.

3. Improved Healthcare:
Over the years, there have been significant improvements in healthcare facilities in India. This has led to decreased mortality rates and increased life expectancy, resulting in a larger population.

4. Declining Infant Mortality Rate:
The infant mortality rate in India has decreased due to improved healthcare services, better nutrition, and increased awareness about maternal and child health. This has led to more children surviving into adulthood, contributing to the population growth.

5. Cultural and Religious Factors:
India is a diverse country with various cultural and religious practices that encourage larger families. In some communities, having more children is seen as a social and religious obligation, leading to a higher birth rate.

6. Migration:
India has a significant number of migrants from rural areas to urban centers in search of better job opportunities and a higher standard of living. This internal migration contributes to the population growth in cities.

Conclusion:
India's large population is a result of various factors such as high birth rates, a large youth population, improved healthcare, declining infant mortality rate, cultural and religious factors, and migration. As a result, India is the second most populous country in the world.

1. China 1,397,897,720 6. Nigeria
2. India 1,339,330,514 7. Brazil
3. United States 332,475,723 8. Bangladesh