Futures is pre-setting the transactions to be done in the future.
Buyers and sellers promised to sell at the price promised at this point and at that price at a certain point in the future.
There are currently restaurant owner A and farmer B.
Currently, the price of rice is $20 in the summer, but restaurant owner A thinks that the price of rice will go up to $30 in the fall, and
farmer B thinks that the price of rice will go down to $10.
So the owner of the restaurant makes a suggestion to the farmer. I'm making a promise to buy rice for $20 no matter what the price of rice is in the fall.
From the standpoint of the restaurant owner and the farmer, there is no reason not to do this contract. They both think they're going to benefit. That's how they sign a "Futures" contract.
If the price of rice really goes to $30, the owner of the restaurant will benefit, and if it goes to $10, the farmer will benefit.
If you sign a Futures contract like this, you must sell rice for 20 dollars no matter what the price of rice is in the fall