Bartering is the process of obtaining goods or services by direct exchange without the use of currency. In times of economic instability or currency devaluation, it can be a great way to ensure the flow of necessary items and services into your household without using precious funds. Historically, face-to-face exchanges between familiar parties were most common, but the Internet has opened up a new medium for bartering opportunities for both person-to-person exchanges and third-party facilitated transactions.
In his analysis of barter between coastal and inland villages in the Trobriand Islands, Keith Hart highlighted the difference between highly ceremonial gift exchange between community leaders, and the barter that occurs between individual households. The haggling that takes place between strangers is possible because of the larger temporary political order established by the gift exchanges of leaders. From this he concludes that barter is "an atomized interaction predicated upon the presence of society" (i.e. that social order established by gift exchange), and not typical between complete strangers.
When barter has appeared, it wasn’t as part of a purely barter economy, and money didn’t emerge from it—rather, it emerged from money. After Rome fell, for instance, Europeans used barter as a substitute for the Roman currency people had gotten used to. “In most of the cases we know about, [barter] takes place between people who are familiar with the use of money, but for one reason or another, don’t have a lot of it around,” explains David Graeber, an anthropology professor at the London School of Economics.