For example, suppose you need to buy 10 tons of plastic in six months, and now the price is 1 000, 1 ton, but the price may rise to 1 500 tons in six months, then you are definitely willing to buy it at 1 000 tons, but you don't need it now, so you can buy it. When signing the contract, you should pay a part of the deposit to avoid one party's breach of contract.

Today's futures are electronic futures. Buyers and sellers don't need to find it themselves. The contract is drawn up by the exchange. You only need to pay the deposit to buy the contract. If you want to break the contract, you can sell the contract without paying the penalty. Other operations are just like stocks.