Answer:
There is no evidence, historical or contemporary, of a society in which barter is the main mode of exchange; instead, non-monetary societies operated largely along the principles of gift economy and debt. When barter did in fact occur, it was usually between either complete strangers or potential enemies.
With barter, an individual possessing any surplus of value, such as a measure of grain or a quantity of livestock, could directly exchange it for something perceived to have similar or greater value or utility