The document discusses key concepts related to population including:
1. Population size, distribution, growth, and characteristics such as age, sex, literacy levels are important to study.
2. India's population in 2011 was 1.21 billion with states like Uttar Pradesh having the largest populations.
3. Components of population growth include birth rate, death rate, and migration. National policies aim to reduce population growth through education and family planning.
4. Population characteristics such as density, age composition, sex ratio, and literacy rates provide insights about development levels across states.