Consider a city having a downtown and a countryside. The part of the city with buildings and (asphalted) streets (downtown) is usually called the "metropolitan area" or "urban area", while the sorroundings are called the suburbs. When we talk about a "metropolis", we mean a CITY, not a town or a village or any small settlement.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.