Google Adsense

Google Adsense is the program run by google , that allows publishers in the Google Network of content sites to serve automatic text,images,videos and rich media adverts that are targeted to site content and audience. These adverts are administered,sorted,and maintained by Google,and these ads can generate revenue on per-click,per-impression basis  

Google uses its Internet search technology to serve advertisements based on website content, the user's geographical location, and other factors. Those wanting to advertise with Google's targeted advertisement system may enroll through Google AdWords. AdSense has become a popular company in creating and placing banner advertisements on a website, because the advertisements are less intrusive than most banners, and the content of the advertisements is often relevant to the website.

Many websites use AdSense to monetize their content; it is the most popular advertising network.

AdSense has been particularly important for delivering advertising revenue to small websites that do not have the resources for developing advertising sales programs and sales people to generate revenue with. To fill a website with advertisements that are relevant to the topics discussed, webmasters place a brief HTML code on the websites' pages. Websites that are content-rich have been very successful with this advertising program, as noted in a number of publisher case studies on the AdSense website. AdSense publishers may only place three ad units per page.