auction types

Auctions are methods for selling items where buyers bid to purchase. In a **timed or English auction**, bids increase until no higher bid is made, and the highest wins. In a **Dutch auction**, the price drops until someone agrees to buy. A **sealed-bid auction** requires bidders to submit confidential offers, with the highest winning. A **reserve auction** sets a minimum price that must be met for the sale to proceed. **Vickrey auctions** are sealed-bid with the highest bidder winning but paying the second-highest price. Each type influences how buyers bid and how prices are set.