In which of the following systems goods are directly exchanged without the use of money?

Barter system

In a barter system where goods are directly exchanged without the use of money, double coincidence of wants is an essential feature. Double co-incidence of wants is an economic phenomenon where two parties each hold an item that the other wants, so they exchange these items directly without any monetary medium. What a person desires to sell is exactly what the other wishes to buy.