How does it work?

Google AdSense is the program that can give you advertising revenue from each page on your website with a minimal investment in time and no additional resources.

AdSense delivers relevant text and image ads that are precisely targeted to your site and your site content. And when you add a Google search box to your site, AdSense delivers relevant text ads that are targeted to the Google search results pages generated by your visitors’ search request.

For more info, please visit:
http://www.google.com/services/adsense_tour/