Descending bids (Dutch auctions)

One of the variants of auction type pricing where there is one seller and many buyers or one buyer and many sellers. In the first kind, an auctioneer announces a high price for a product and then slowly decreases the price until a bidder accepts the price. In the other, the buyer announces something that he wants to buy and then potential sellers compete to get the sale by offering the lowest price. Each seller sees what the last bid is and decides whether to go lower or not.