They say it's a small world, but is this phrase really about the size of the world, or the weird fact that sometimes, strange coincidences happen? I say the latter because well, our world is huge. Huge, complicated, awesome, and at the same time, tragic and terrifying.
For all these reasons, we tried to show off a variety of human life and creation in the 10 "biggest cities" in the world.
Now, you may be asking what the quotes are all about, and the truth is that quantifying the biggest cities by population is actually an insanely difficult process, with a barely scientific answer.
The easiest way to do this would be to take a bonafide city, an area of buildings and land controlled by a local government, and compare their numbers to other cities, but this is the least accurate way of doing it too! After all, if a city literally touches another city, are they really separate? Sure, technically they are, but in the average person's day to day life, they aren't. So, for this reason, we used the broader term "metropolitan area." These areas include multiple "cities" that are very close to each other to arrive at a greater population, but the areas have more to do with how a city actually functions for its residents, rather than merely who governs whom.
We used the Fortstall numbers from this Wikipedia page.