urban(adj)means of, relating to, or located in a city /
Characteristic of the city or city life.
downtown(adj)means of, pertaining to, or situated in the main business section of a city
所以我認為哦，urban 主要指城市的，市內的，
而downtown 主要指市中心的，商業區的（最繁華的街區，就像南京新街口）