Definition - What does Header Bidding mean?
Header bidding is a method where publishers can offer inventory to competing parties in real-time, i.e. before putting ad servers in play. It is a type of automation that helps bridge inefficiencies and can help publishers avoid leaving money on the table in bidding for impressions.
Header bidding is also known as advance bidding or pre-bidding.
Techopedia explains Header Bidding
Experts in digital advertising are promoting the idea that header bidding evolves these types of ad sales from previous methods, many of which involved “waterfalls” where publishers would offer ads sequentially in different markets, hoping for a buyer. Now, header bidding offers a more versatile and quick merchandising strategy for publishers with available ad impressions. It is a way to innovate the market to produce better and more efficient results.