Economic History

Step 1: Understanding the Concept:
The question asks for the name of the earliest form of trade, which involves exchanging goods and services directly for other goods and services without using a medium of exchange like money.

Step 3: Detailed Explanation:
The Barter System is the oldest form of commerce. In a barter system, two parties directly exchange goods or services that they have for goods or services that they want. For example, a farmer might exchange a bushel of wheat for a pair of shoes from a shoemaker. This system relies on a "double coincidence of wants," where both parties must have what the other desires. The other options are irrelevant or incorrect terms for this concept. The Salarium system refers to payment with salt in ancient Rome, which was an early form of currency, not barter.

Step 4: Final Answer:
The direct exchange of goods in primitive societies is known as the Barter System.