Google's program that pays website owners for displaying ads is AdSense.
Launched publicly in 2003, AdSense lets publishers place Google-managed advertisements on websites, blogs, and other content pages. Google selects ads using factors such as the page's subject, the visitor's location, and advertiser bids. Publishers can earn money when users interact with ads or when eligible impressions are recorded.
AdSense grew from Google's contextual-advertising technology and was strengthened by Google's 2003 acquisition of Applied Semantics. Its name was adopted from Applied Semantics' own product. The program helped smaller publishers monetize traffic without negotiating directly with individual advertisers.
A common mix-up is Google Ads, which is primarily the advertiser-facing service used to buy campaigns. AdSense is the publisher-facing network. DoubleClick was another Google advertising brand, while AdMob focuses mainly on advertisements inside mobile apps.