i wish someone could explain to me this in english, I understand that a short is betting that it will go down, long the opposite, but how does it work in detail? can someone give me an example? like they were explaining it to a 5 year old? lol.

Why does it matter that there are 7300 shorts? because thats a shit ton?
Short: Somebody borrows bitcoins and sells them. Later he will buy bitcoins at lower price and returns them to the lender + interest.
Long: Borrow $$ then buy BTC and sell them later.
On Bitfinex, they have a claim option. If you buy 10 coins at $100, and the price goes up $20, you have $200 profit (10 coins x 20 USD).
You can sell 8 coins, and use the $200 profit to "claim" the remaining 2 coins at the original $100 price.
This means you don't necessarily have to sell all of the original 10 coins.
this just sounds so damned confusing, lol and extremely risky..But very profitable if you guessed the right way. Also, this only works by borrowing either coins or money, right? there needs to be a class on this somewhere, lol.. bitfinex explains it like you already know what you are doing..