The CDE auction house is a place where MYCDE users can place there items in an auction- off bid for a period of time.
The auction house allows users to have a bid on their items! you simply post your item in the AH with a start off bidding price and a time frame and let the MyCDE users bid their CDs for you item you posted.!
Auction House location-Edit
The AH can be found on the left side of you profile under that catagory "Stores".