spot trading means paying with one hand and delivering with the other. At the current market price, you can buy as many goods as you want and sell as much as you want.

Futures, as the name implies, are "forward goods", which is essentially a "transaction contract".

In this contract, the specific commodities, prices, quantities and delivery time are specified.

For example, in a trading place (futures exchange), there are two parties A and B, and

they sign a contract (A has something and wants to sell goods; B has money and wants to buy goods), and it is stipulated that the handover of money and goods will be completed by a certain time.

In order to ensure the performance of both parties, the Exchange requires that both parties A and B must each take out a certain amount of deposit (security deposit) and deposit it into the account designated by the Exchange.

halfway through, A doesn't want to perform this contract for some reason, but another trader, C, is the same as A (has something and wants to sell goods).

Then C takes over this contract, and both parties become C and B.

At the same time, A's deposit in the exchange is funded by C.

this change will also happen in party b, and it can be more than once (before the physical delivery time).

So futures trading is actually not buying and selling "physical objects", but trading this "contract".

The above is a very popular introduction. Are you satisfied?