One core place that shorting is key (which isn't touched on much) is shorting/going long on commodity futures. Very simplified example below:
If I'm an airline (and my business is dependent on the price of oil) and I think the price of oil will go up, I will hold some amount of oil futures at the current price. If the price of oil rises, my company is "hedged" against that rise. This is good for the buyer of the commodity. If the price of oil goes down, I lose on my future, but my business is fine overall.
Correspondingly, if I'm the seller of a commodity (I own an oilfield), I might short oil futures, in case the price goes down. I make less money selling my oil, but I hopefully make some back on the short
If I'm an airline (and my business is dependent on the price of oil) and I think the price of oil will go up, I will hold some amount of oil futures at the current price. If the price of oil rises, my company is "hedged" against that rise. This is good for the buyer of the commodity. If the price of oil goes down, I lose on my future, but my business is fine overall.
Correspondingly, if I'm the seller of a commodity (I own an oilfield), I might short oil futures, in case the price goes down. I make less money selling my oil, but I hopefully make some back on the short