Downtown refers to Centretown are, bounded by Bronson and Elgin from west to east, and by Laurier and Ottawa river from south to north. Of course the market area may be considered downtown as well due to its popularity and night life diversity.
Hampton Park refers to the north side of Carling and Kirkwood area, while south keys comprises Bank and Hunt Club area, and Bayshore is close to the intersection of 416, Carling and Richmond. Usually those areas are easily identified by their shopping center, i.e. South Keys plaza, Bayshore shopping centre...