Futures are valuable contracts protected by law only because there is no spot physical delivery. After a certain period of time stipulated in the contract, the seller sells a certain number of contract subject matter to the buyer at a specified price, and the spot price of the subject matter is available after the expiration. The difference between the two prices multiplied by the contract quantity is their respective profits and losses.

Futures are relative to spot. If you buy it, you don't trade now, and then trade after the contract expires. The biggest difference from spot trading is that you use margin trading, and generally you don't need physical delivery after maturity. The so-called margin trading.