Stockfish is unsalted fish that is naturally dried by the sun and wind on the racks or (more rarely) dried in special drying houses. To dry food is the world's oldest known preservation method, and dried fish will keep for years. The method is also cheap, the work can be done by the fisherman and the fish makes easier to transport to market. Drying fish is old in Norway, the word "cod" comes from the old Norwegian turskr meaning turrfiskr (stockfish).