You can buy the "right to buy later" from the beginning. You can buy such a right when you expect the price of xx commodity futures or futures to rise at some point in the future. When the price rises in the future, you can buy it and sell it in the spot market. The difference between the two is your income. If you predict the future price, the price of goods will fall, and you can buy a kind of "right to sell futures in the future". When the future comes, you can buy it in the spot market, and then the difference between the two is the income.
However, when you buy a right and later find that you made a mistake, you can sell it immediately to reduce your loss. The act of selling this right is a kind of "reverse liquidation".
Physical delivery is on the due date, and you have to hand over the goods before you can buy your goods, so that your money and goods are clear.
However, when buying financial instruments such as futures and options, you don't really need to deliver the goods, just the rights.
For example, if you buy soybean futures, the seller will not really give you a certain amount of soybeans.