what is shorting, page-5

A short position is simply one that will profit from a negative (bearish) movement in the security price.

The process of shorting is usually, at least in the big league, done via that borrowing process explained above. Another way is to simply take a short position with a broker or other intermediary (e.g. CFD provider) and let them worry about the detail.

Note you can sell borrowed stock today and expect to buy the cover stock (cover your short position) later.