I am new to this too. However, I believe a short is someone who actually makes money when the stock price goes down. Shorters have an interest and gain when the stock price goes down (personally, I think this should not be allowed in our captialist society. I think it is detrimental and cynical) It is like betting in a sports game, but making money by predicting that one team will lose, and betting on that losing team---very loose analogy, since our economy should not be viewed as a game.
Short is for holding a stock for a short time IE 2hrs to maybe a month or so. Not "short selling" and Long or longs are people that are holding the stock for a long time.