There are mainly two major types of soy sauce, and they are categorized by use: regular soy sauce and soy sauce for soup (Guk-Gan-Jang). Regular soy sauce is widely used in Korea for seasoning, marinating and braising, and is similar to the soy sauce you see in Japan or North America. Soy sauce for soup, however, is unique to Korean cooking. As the name suggests, soy sauce for soup is mainly used for soup. But it is also used for "namul" (Korean vegetable side dishes) and seasoning other dishes. Since it"s much saltier and lighter in color than regular soy sauce, you can use a small amount to season your soup while keeping the soup color nice and clear. If you want to do proper Korean cooking, you should have both regular soy sauce and soy sauce for soup (Guk-Gan-Jang). Sempio Naturally Brewed Soy Sauce 501 is a great choice for regular soy sauce. It is naturally brewed with a 5 step fermentation process that lasts 6 months, unlike Jin-Gan-Jang which is chemically produced. It also has a TN number greater than 1.5. The TN number indicates the percent of actual soybean protein that is contained. The higher the TN number, the more premium the soy sauce is. (A TN number of 1% is average, 1.3% premium, and 1.5 - 1.8% super premium.) It also contains no preservatives.Sempio Naturally Brewed soy sauce 501S has been the number one soy sauce in Korea for 14 consecutive years. (AC Nielson 1997-2010)