REO Courtesy of WikiPedia.com http://en.wikipedia.org/wiki/Real_estate_owned 

Real Estate Owned or REO is a term frequently used by lending institutions as applied to ownership of real property acquired for investment or as a result of foreclosure.
REO means - Property owned by a lender - usually a bank - after an unsuccessful sale at a foreclosure auction. This is common because most of the properties up for sale at these auctions are worth less than the total amount owed to the bank: the minimum bid in most foreclosure auctions equal the outstanding loan amount, the accrued interest and any fees associated with the foreclosure sale.

If the property is real estate owned, the bank will then go through the process of trying to sell the property on its own. It will try to remove some of the liens and other expenses on the home, and then try to sell it on the market. Real estate investors will often go after these properties as banks are not in the business of owning homes and, in some cases, the house can be bought at a discount to its market value.