The adjective “urban” describes city areas and “rural” describes the country. But in between those, there are places near the city with many houses. They are “suburban” (“sub” means “below”—they are not quite city but still not rural). Many people live in the suburbs and go into the city to work.
urban という形容詞は「都会の」という意味で、 rural は「田舎の」です。都会と田舎の中間で家がたくさんある地域はどちらにも該当しませんね。この地域は suburban 「郊外」です。（ Sub は「下」という意味で、都市とまでは言えないが田舎でもない）たくさんの人が suburb に住んで、都会で働きます。
