It is slightly sweetened, so it is more palatable on its own than Unsweetened Baking Chocolate or Bitter Chocolate are, but it is not sweetened as much as Semisweet Baking Chocolate is.
Extra cocoa butter is usually added. The best brands will list cocoa butter as the only fat used in making the product.
Bittersweet Chocolate is dark.
Half Unsweetened Baking Chocolate and half Semisweet Chocolate.