The world is composed of 195 independent countries, 72 dependent areas and other entities. The countries with the most population (in descending order) are China, India, the United States, Indonesia, Brazil, Pakistan, Nigeria, Bangladesh, Russia and Japan. Just slightly above 50% of the people on the planet live in an urban area. The average life expectancy at birth in 2013 is 66 years for males and 70 years for females.
Incredibly, over 66% of all the adults in the world who are unable to read or write are found in just 8 countries. These countries are China, India, Indonesia, Bangladesh, Nigeria, Egypt, Pakistan and Ethiopia. Of the adults unable to read and write, 66% of them are females.
The most common first languages spoken are Mandarin Chinese, Spanish, English, Arabic and Hindi.
Only three countries on the planet, Burma, Liberia and the United States, have yet to adopt the metric system as their official standard for weights and measures.
World's Biggest Political Systems
The political system of the world's three largest countries, in terms of population, are the following.
China is a communist state with only one political party (Chinese Communist Party or CCP) and no substantial political opposition groups. The country's President and vice president are elected by the National People's Congress for a five-year term.
India has a federal republic type of government where dozens of national and regional political parties exist. The President is elected, using an electoral college, composed of Parliament members and legislatures. The President is elected for terms last five years with no limit on the number of terms they can serve.
The United States is a constitution-based federal republic that has, as of July 2012, four main parties: Democratic, Republican, Libertarian and Green. The President and Vice-president are elected together by a college of representatives (the electoral college) who are elected directly from each state. They serve for a four-year term with eligibility for a second term. The U.S. Congress consists of a Senate (2 elected members of each state who serve six-year terms) and the House of Representatives (who serve two-year terms).