Which system practised in exchanging their goods?

The system commonly practiced in exchanging goods is known as barter. In this system, individuals or groups directly trade goods and services without using money as an intermediary. Barter relies on the mutual agreement of value between the parties involved, making it essential for them to find a suitable trading partner. While effective in some contexts, barter can be limited by the need for a "double coincidence of wants," where both parties must desire what the other offers.