Birth rate
According to the CIA's "The World Factbook", the country with the highest birth rate is Niger at 6.49 children born per woman and the country with the lowest birth rate is Taiwan, at 1.13 children born per woman.
Developing country
Over the last few decades, global population growth has largely been driven by developing countries, which often have higher birth rates (higher fertility rate) than developed countries. According to the United Nations, family planning can help to slow population growth and decrease poverty in these countries.