Salt was once considered a luxury item, nicknamed "white gold." Only the rich could afford to use it. The Romans used it as money to pay their soldiers for their service to the state. The Chinese also used it as money. Today, salt is plentiful and accessible worldwide. It comes from two sources: rock and sea.
Rock salt is mined from natural deposits formed years ago by the shrinking of the seas. Sea salt, like its name suggests, is taken from salt marshes and basins where seawater once was trapped and evaporated, leaving the mineral deposits behind.
Salt in cooking is used to preserve meat, cheese, and fish to enhance the color, taste, and texture of foods like vegetables and to slow the growth of yeast in baked goods like bread, cookies, and cakes. It stimulates the appetite and just makes food taste good, overall.
Cook's Note: Store salt in airtight containers in a dry place. To keep moisture from causing salt to clump, add a few grains of uncooked rice to the salt shaker.