This refers to the selling of an asset by public auction. The potential buyers bid against each other under the leading of the auctioneer, and usually the highest bid will be accepted. It must comply with several laws and it must be advertised very well.
a second chance bidding system to get names that were previously won by another member who failed to remit payment for the name
In the case of the execution of a mortgage, sale or disposal of goods which are awarded to the highest bidder out of those who bid. It can be legal (by court order) or extralegal (in the presence of a solicitor.)