Uptown is a relatively new neighborhood name. It includes portions of what was once considered downtown and Koreatown Northgate. Some people still identify with the old neighborhood names.
Uptown generally runs along Telegraph Avenue and Broadway from 18th or 19th streets to 25th Street (give or take). The Koreatown Northgate business district considers its southern boundary 20th Street, and there are definitely Korean businesses as far south as 24th Street, but Uptown goes at least as far north as 25th Street.
Popular neighborhoods include Uptown, Rockridge (College Avenue from Broadway to the Berkeley city limit), Temescal (Telegraph Avenue from 42nd to 51st streets), Piedmont Avenue (from MacArthur Blvd. to Pleasant Valley Avenue) and Grand Lake (Grand and Lakeshore avenues northeast of Lake Merritt). Jack London Square (foot of Broadway) has some appeal, too. Fruitvale and the Laurel District are mixed; Jingletown is not recommended.