This video shows the Top 10 countries with most population in 2019 to 2050. The population ranking includes well known most populous countries such as, China, India, US, and Indonesia; it also shows some future predictions. Countries such as Nigeria, Pakistan, Bangladesh, Ethiopia, and Congo will be possibly ranked in the top 10 in the near future. 10 most populated countries- 2019 vs 2050 Population refers to a collection of humans. Demography is a social science which entails the statistical study of human populations. Population in simpler terms is the number of people in a city or town, region, country or world; population is usually determined by a process called census.