If you want to advertise your site using the Google network here is the answer for you.
Google provides the famous AdWords platform where you can advertise any product or service you may have. You will need to have a website to showcase the product or service or information. This service is not free so you will have to pay for the advertising.

The ads you put will be displayed across the world wide web using the Google Adsense platform that millions of publishers use today. Bulk of the add impressions come through google search. Others include third party publishers who have put adsense service form google on their sites and have content related to the keywords you are advertising for. You pay only when someone clicks your ad. There are display and impression ads too that charge you for display only.

In case you want to put Google ads on your site then the answer is Adsense. You may check the reference link for more information on Adsense.