A Bidder is a system or algorithm that places bids on behalf of an advertiser in real-time auctions for ad impressions. Bidders analyze data from bid requests to determine bid amounts and ad relevance, ensuring ads reach the right audience.

Bidders streamline the bidding process, allowing advertisers to compete effectively in high-speed auctions. By using smart bidding algorithms, advertisers can maximize ad exposure, improve targeting, and achieve cost-effective placements.