How does "future contract" of Bitcoin work?

[SherryHurry]

A futures contract is an agreement in which a buyer and a seller agree to exchange goods (such as corn, wheat, gold, oil, shares, and in this case an electronic currency) into one. certain days in the future, at the agreed price at the present time. The transaction will be paid in cash.

In futures contracts, investors place bets on asset price volatility trends, particularly as they are often used for short positions, ie bets that prices will fall.