Salt has many faces and, believe it or not, many flavors. Most salt sold commercially today is rock salt, which is mined out of the ground from salt deposits left behind by ancient, extinct seas. You can also buy sea salt, which comes from existing seas and is simply seawater that has been evaporated by the sun. There are substantial differences in the flavor of various sea salts depending on origin. Some have a strong mineral taste, while others taste of seaweed, and still others are almost sweet.