Final answer:
After depositing their gold, people began using coins as a form of currency to facilitate easier and more efficient trading of goods and services.
Step-by-step explanation:
Once people's gold was deposited and they no longer needed to travel with large amounts of goods for trading, they started using a form of currency. The Lydians, in particular, began to create coins from lumps of gold and silver with a standard weight, known as shekels, around 650 BCE. This allowed for easier and more efficient trade of goods and services, which was further streamlined by the widespread establishment of early legal systems that determined monetary value and structures of taxation. Before this, bartering was the common means of trade, but as economies developed and trading across areas like the Sahara increased, the demand for goods such as salt, gold, copper, and later other commodities grew and these began to be traded extensively across regions.