Futures is a trading system. Generally speaking, opening a position is to buy or sell a contract without a contract in hand. You may wonder, how can you sell it first without a contract? This is precisely the particularity of the futures long and short system. Closing a position is to sell or buy back the contract in your hand, so that there is no contract in your hand. Long positions are equivalent to giving something to others, and others will pay you back; Short positions and positions are equivalent to people giving you something, and then you give it back. I hope it helps you.