This thread remembers me of memories years, and years and yeras back when I was trying to understand how a short worked. But even when I understood it, I noticed that it was difficult to explain to people who didn't know anything about stock trading (or even some that did some casual trading..ehhh... investing.. you know.. buy-and-hold).
So I always use the following example: Imagine you are looking for a used car. And you tell me that you are prepared to spend 10k on a model XYZ. I, being well introduced into the car market , know that I can (probably) find that car for 8k somewhere. So I tell you: "ok, I sell you that car for 10k, and I deliver it in 2 weeks". So I sold you something I don't have yet. Then I go hunting for that model and when I find it , for 8k, I buy it and deliver it to you 2 weeks later. Profit for me : 2k.
What's the difference with stock trading? Almost nothing. The only difference is, that in my car example , if I couldn't find it, I could say "Well, you know I had some trouble finding it blablabla", and could try to cancel the sale to you. With stock trading you HAVE to deliver the buyer. So if I promised the car, and I have made a mistake in my judgement and I can only find that particular model for 15k, I HAVE to deliver it to you for the agreed price (10k). Loss: 5k for me.
Maybe the explanation is a little bit lengthy but I hope you understand better now how a short works and what it is.
TFD