Also known as seller financing.
The buyer of the property is financed by the seller instead of getting a mortgage through a traditional lender.
Instead of receiving a lump payment for the property, the seller agrees to accept payments. Under this scenario, the seller forgoes the having the lump sum for another property from the sale of this one.
Another drawback is the seller is taking on the risk with the buyer. If the payments are not made, the seller has to go through the foreclosure process. The move can be beneficial if the buyer makes the payments since the seller also earns the interest.
From the buyer's perspective, owner financing could get one around credit hassles. For example, one might have the income to support the payments yet be lacking in credit history/bad credit which would not make a conventional loan possible.