The process begins when a user visits a website. This triggers the site to send an ad request to an ad exchange. The exchange then conducts an auction among advertisers for the ad space, considering factors such as user demographics, behavior, and other data. The highest bidder wins, and their ad is displayed to the user in real-time. This entire process takes milliseconds, ensuring efficiency and relevance. This technology is often linked to demand-side platforms (DSPs) and supply-side platforms (SSPs) that facilitate the transaction.