What is the essential feature of a barter system?

• Barter system:
The barter system is a direct exchange of goods and services.
It requires the double coincidence of wants.
The barter system eliminates the use of money.
It generally flourishes among uncivilized and backward communities.
This system has been practiced for centuries and long before money was introduced.
People started exchanging services and goods for other services and goods in return.
Today, bartering has made a considerable comeback using more sophisticated techniques to aid in trading, for instance, the Internet.
In ancient times, this involved system people in the same area; however, today bartering is global.
The value of bartering items is negotiable with the other party.
Bartering is usually conducted directly between two parties; however, it may be done multilaterally through a trade exchange.
In times of monetary crisis, a barter system is often established as a means to maintain the trading of goods and services as well as to hold a country functioning.
This may occur if physical money is not available or if a country sees hyperinflation or a deflationary spiral.