How Google Adsense Works ?

1. Adsense JavaScript code is inserted by the webmaster into a webpage.
2. This page is each time visited, the JavaScript uses the online J SON to display the contents fetched from Google's Servers.
3. For contextual advertisements, to determine a high-value keywords Google's servers uses a cache of the page. If the keywords are cached already, those keywords based on the AdWords bidding system advertisements are served.
4. 
   For the site-targeted advertisements, the advertiser chooses the page/pages on which advertiser display the advertisements, and pays based on cost per mile (CPM), or the price which is chosen by the advertisers to pay for every thousand advertisements displayed.
5. For referrals, when visitors either download the referred software or subscribe to the refereed service, Google adds money to the advertiser's account. In August 2008, referral program was retired.
6. After the visitors perform the search, the search advertisements are added to the list of results.
7. When the page is requested the Web browser sent the JavaScript, the JavaScript code is possible for the other websites owners to copy and add on their own webpages. To protect against of this type of fraud, Adsense customers specify the pages on which the advertisements should be shown. Adsense then ignore the clicks other than those which are specified from pages.