Client-side header bidding is all about control and monetization — it focuses on standard ad formats. When the user types in your URL, the header bidding code on the website’s header begins to send requests to the third-party platform. That’s when you start receiving bids and once the highest bidder wins, it’s passed on to your server. Then, the winner competes with your deals and once the highest bidder is selected, your server displays their ads.
In contrast, the server-side header bidding container follows a similar concept. However, requests are being sent from a central server. You don’t need the user’s browser for the code to begin to send requests to the platform. This is more commonly referred to as open bidding.