For example:
You have a batch of goods to sell in the future, but you are worried that the spot market price will fall, so you are shorting (selling) the corresponding goods in the futures market now. When you want to sell a commodity, if the market price really falls (generally speaking, the futures price of the corresponding commodity will also fall), you must close the short position (that is, buy) established in the futures market. At this time, the money you earn less in the spot market is compensated in the futures market (because you sell high and buy low in the futures market). If it goes up, you will lose money in the futures market, but the extra money you earn in the spot market can be used to make up for the money you earn in the futures market.
or vice versa, Dallas to the auditorium
Hedging is not used to make money, but to prevent risks, and there is no absolute guarantee of complete hedging.