The market is a concept. If you are growing tomatoes in your backyard for sale, you are producing for the market. You might sell some to your neighbors and some to the manager of a local store. But in either case, you are producing for the market. Your efforts are directed by the market. If people stop buying tomatoes, you may stop producing.
If you take care of a sick person to earn money, you are producing service for the market. If your father is a steelworker or a truck driver or a doctor or a grocer, he is producing goods or services for the market. When you spend your income, you are buying things from the market. If you spend money in stores, supermarkets, gas stations, and restaurants, you are buying from the market. When the local grocer hires you to drive the delivery truck (送货车) , he is buying your labor in the labor market.
The market is everywhere, and it's very real. If nobody buys your tomatoes, it won't be long before you get the message. The market is telling you something. It's telling you that you are using energies and resources in doing something the market doesn't want you to do.