Simply put - it's anything but short!!
A short sale occurs when a seller owes more (to the bank) for his house than it is worth (more than the potential sale price)
The seller asks the bank to forgive him the difference between what is owed and what it may sell for, and allow him to sell the house for that lower amount, even though he or she won't be able to pay off the mortgage in full.
Not everyone can just do a short sale.
In order to qualify for a short sale you'd need to show some sort of hardship - financial due to job loss, medical issues, divorce, etc. There is a packge (lots of paperwork) that will be filled out and presented to the bank for their approval.
You may attempt to sell your home, and accept an offer. That offer is then sent to the bank and subject to the bank's final acceptance.
This entire process can take many months, and there is always the possibility it will never close.
Hope this helps............