downtown : to or in the centre of a city or a town: do you wprk downtown? uptown : to or in the northern area of a city or town, or in the area where the richer people live: the adams live uptown.

Fofa's answer is very good; most big cities in America do not have an uptown. New York City is the only city I can think of with a real uptown. It also has a West Side and an East Side, a Midtown, and a lot of special names which other American cities lack. There is no uptown in Los Angeles, for example; we have Bel Air and Beverly Hills here which have a very uptown connotation. Downtown is not a specific geographic place and we never go TO it, we simply go there. In the military "going downtown" means aerial bombardment of that city. Good Q

This is an American expression. It is not used in Australian English.