What type of auction features bidders competing against each other in real-time?

An English auction is characterized by bidders actively competing against each other in real-time, typically in an ascending price format. This type of auction begins with a minimum starting price, and participants raise their bids until no one is willing to bid higher. The highest bid at the close of the auction wins the item. This live interaction creates a competitive atmosphere, allowing bidders to gauge each other's interest and adjust their strategies accordingly.

In contrast, a Dutch auction involves a descending price approach where the auctioneer starts with a high price and lowers it until a bidder accepts the current price. Sealed auctions, where bids are submitted privately and not revealed until the auction concludes, do not allow for real-time competitive bidding. Online auctions can vary in format, including both English and Dutch, but the specific context of 'real-time' bidding points to the English auction format as the correct response.