What is "Google Adsense" ?

*www.google.com/adsense/
www.google.com/ads/
en.wikipedia.org/wiki/AdSense
adsense.blogspot.com/

Simple. Google Adsense is a program by google (ofcourse) which users who own some website, webspace or such similiar stuffs can sign up to so that they can display Google Ads there. When ppl click on the ads the user will get a % of the money gained by Google and when the money stacks up to 100$ or more Google send the money to you.

There are so many threads already running on this!