Close position = close position, sell the original, and sell (short) the original. Reverse trading and flat position are terms used in hedging, which means that if you make more than one order at the beginning, you will generally close your position by shorting it at maturity.

It is suggested to try spot gold trading, 24-hour online trading, two-way operation of buying up and buying down, and delivery on the same day without any time limit. It is a simple and flexible T+0 transaction. I suggest you download a free simulated trading software directly, try 24-hour online two-way trading, and then enter the real trading after you are proficient.