How RTB actually works- The simple way to know the complex process

Now a days RTB is one of the hot topics in the digital marketing world. Most of us very much confused on this mechanism. Here is the simplest  way to grab the concept>

 The publisher places a tag onto their site as usual, except this tag is enabled for RTB.

 When the user's browser loads the publisher's site it downloads the page and the tag.

 When the browser processes the tag it requests content from the Ad Exchange.

 On receiving the request, the Ad Exchange initiates an auction.

Bidders (e.g. advertisers, agencies etc) enter their bids which include the bid amount and the ad tag they want to show if they win the auction.

The Exchange picks a winner and returns as response back to the browser that contains the winning ad tag.

The browser now loads the ad tag as usual which means loading the creative from the ad server as usual

Again, this all happens in the blink of an eye - typically under 200ms