Chinese black vinegar has very distinctive flavors that come from the fermentation of rice and other whole grains like barley.  This has a nice, slightly smoky, slightly sweet, almost plum-like, piquant flavoring that makes it a great complementary component for a variety of dishes.  This is the sweeter variety of black vinegar that is better suited for dipping (steamed buns, steamed dim sum dishes), rather than the cooking variety (which trends towards being more astringent, with stronger vinegar flavor), albeit it is completely suitable to cook with.