Salt (NaCl), sodium chloride, mineral substance. The mineral form halite, or rock salt, is sometimes called common salt to distinguish it from a class of chemical compounds called salts.
Salt production is one of the oldest chemical practices performed by man. Although salt is produced naturally when seawater evaporates, the process can easily be reproduced to create a higher yield.
Besides being the only mineral you eat, salt is one of the fundamental catalysts of food chemistry. Salt is of course salt. Aside from the elements that make salt, it is always the same no matter how it is packaged.