AdSense is a program operated by Google that places advertisements from members of Google’s AdWords program on individual websites or on RSS or Atom feeds. The ads that are shown are chosen based on relevance to the website’s content or feed articles.
Websites enrolled in the AdSense program earn money each time a visitor clicks on an advertisement. Google handles the advertiser billing and ensures that the owner receives payment.
Website owners can choose how they want the ads to appear on their site and can block those that they do not want to appear. Once enrolled, Google provides an AdSense interface that allows site owners to view data on how the ads are performing, check earnings, view reports and receive important AdSense alerts.
An AdSense for Search program is also available. A search box is placed on the website and each time a visitor uses it to search the site or the Internet, the owner may receive 51 percent of the earnings that Google is paid from advertisers. Payment depends on whether the visitor clicks on an AdWords advertisement as a result of the search.