Here's the first stage of a circular flow diagram. The reason the resource owners gave up their resources in the first place was to get goods and services that they wanted to consume. For example, when you take a job you give up your labor resource to get paid, so you can buy goods and services you need. A market economy has two circular flows. In a market system, every good or service that flows is sold and bought, so every flow of real stuff has a flow of money in the opposite direction.
Real stuff flows from seller to buyer.
Money flows from buyer to seller. For our diagram, we need two circular flows, one in each direction. One direction is resources, goods, and services. The other direction is money. Even though there are two flows, economists generally call it the circular flow.