When we think of money today, we picture it either as round, flat pieces of metal coins; or as printed paper notes. But there are still parts of the world today where coins and notes are of no use. They would buy nothing, and traveler could starve if he has none of the local " money " to exchange for food. Among isolated peoples, commerce usually means a direct exchange of goods. Perhaps it is fish for vegetables, meat for grain, or various kinds of food in exchange for pots, baskets, or other manufactured goods. For this kind of simple trading, money is not needed. But there is often something that everyone wants and everybody can use, such as salt to flavor food, or iron and copper to make into tools and vessels. These things are still used as money in the remote parts of the world today.