Pending
The real estate term "pending contract" means that someone has made an offer on the property and the seller has accepted. Typically contingent on a home inspection to the buyers satisfaction and financing. There could also be a home sale contingency which means the seller has an escape clause typically if another buyer comes along.
Short Sale
A short sale is a sale of real estate in which the net proceeds from selling the property will fall short of the debts secured by liens against the property. In this case, if all lien holders agree to accept less than the amount owed on the debt, a sale of the property can be accomplished.