Google AdSense is a free marketing program which helps online publishers generate revenue through the display of relevant ads on their websites. Publishers may add a custom search engine to their website in order to earn money from advertisements on the search results page when visitors to the site use the search engine. AdSense also helps publishers and website owners to monetize their websites by displaying advertisements directly on their site(s). They may earn money from both impressions or clicks and customize the Google ads which are shown based on their site content and keywords. Other options from AdSense.com include ads for mobile and app users.
In order to use AdSense, folks must first register for the site. Once registered, users can login to their account at AdSense.com and add or change their account settings. Users can also check on their ads, allow or block ads, and view performance reports from AdSense. Reports are available by day, week, or month and include estimated earnings, page views, clicks, page click through rate (CTR), cost per click (CPC), and Revenue per thousand impressions (RPM) as well as other metrics.
The basics of How AdSense Works are that the website owner adds JavaScript code from AdSense into their webpage. Then when someone visits that webpage, AdSense displays advertisements relevant to the page content. If that visitor clicks on one of the ads from AdSense, the website owner has the potential to make money from the ad.
AdSense offers extensive training information and a help forum for their customers. The AdSense.com website also features “Success Stories” from publishers who have grown their sites through the use of AdSense. 
