Barter is defined by the lexicographers at Oxford Dictionaries as Exchange (goods or services) for other goods or services without using money.

How is barter different to the gift economy?

Barter is a negotiated trade of value. The gift economy is giving to an individual or community without an explicit agreement for anything in return. Historically, the gift economy was common. In a traditional economy, a farmer who enjoys a bountiful harvest may have been expected to share it with the community.

simplicable.com/new/barter

"Generally, barter is a cumbersome and inefficient means of organizing exchanges in an economy, since a large amount of time is wasted in seeking out and finding compatible 'swap' partners (i.e. each selling what the other wants to buy), and then haggling over an appropriate exchange rate (for example how many tomatoes equal a sewing machine?)."

financial-dictionary.thefreedictionary.com/barter