The advent of airplanes made it possible for people to travel around the world with greater ease and flexibility. Travel by land and sea must overcome friction and barriers. Travel by air, however, is mostly unimpeded and smooth gliding (with the occasional turbulence) and much much faster. With each passing year, air travel has become cheaper and more convenient (although the convenience is arguable), and people take to the skies with ever increasing numbers. Connecting all their flights are the hubs of the sky, the airport. In this post, we'll introduce you to the world's 10 busiest airports in terms of passenger traffic.