An ad network is a platform that connects advertisers with publishers who want to display ads on their websites or apps. Advertisers pay the ad network to promote their products, while publishers earn revenue by displaying these ads. The ad network acts as an intermediary, helping both parties find suitable matches based on audience and content. Ad networks use various technologies to target specific audiences, ensuring that the right ads reach the right people. They analyze user data and behavior to optimize ad placements, which can lead to higher engagement and better returns for advertisers. Examples of ad networks include Google AdSense and Facebook Audience Network.