Earn money from relevant ads on your website
Google AdSense matches ads to your site's content and audience, and depending on the type of ad, you can earn money from clicks or impressions. AdSense for content automatically crawls the content of your pages and delivers text and image ads that are relevant to your audience and your site content.
Here is what Google has to say:
It's also a way for website publishers to provide Google web and site search to their visitors, and to earn money by displaying Google ads on the search results pages.
Google Adsense is incredibly easy to use:
1) Have a website or blog with a substantial amount of content.
2) Visit the Google Adsense website to sign up for an account. If you don't have a Gmail address, you'll need to create one before creating your Adsense account.
3) Copy the html code generated by Google into your blog or website.
4) Sign into the Google Adsense website to check your balance. You get paid for the number of times visitors to your blog site click on the ads placed there.
5) Collect your payment via check, direct deposit, or other options.