Barter
The act of exchanging a good or service for another good or service.
The fundamental idea of bartering doesn't work on even a slightly larger scale than occasional individual trades. In order to operate, you need two willing participants who each provide what the other needs and are willing to trade.
These coincidences don't provide optimal conditions for fair trade and aren't that easy to maintain. Thus the need for items that hold somewhat equal value to everyone. These have developed over the years to their current most popular forms of cash and gold.