What is "Tokyo"?

Tokyo is rightfully described as a metropolis - now used as a shorthand for the Greater Tokyo Area. More than just a city, Tokyo is the most populous metropolitan area in the world and it certainly feels that way. Commuting around the area is easy by foot, bike or train but it seems that no matter how far you go, you are still in the city. Despite its size, the city is clean, safe, and welcoming. It's a city that everyone should visit at least once in their life; if they don't mind the occassional crowd, that is.