What is the Google Network?
The Google Network is a large group of websites and other products, such as email programs and blogs, who have partnered with Google to display AdWords ads. Advertisers have the option of running their ads on Google as well as the Google Network for no extra cost.
AdWords ads are placed based either on searches or website content, so the Google Network has two components: the Search Network and the Display Network.
Who's part of the Google Network?
Google is always expanding the number of sites and products in the network through premium services, online Google AdSense program, and DoubleClick Ad Exchange. Participating websites must adhere to Google AdSense standards.
Besides appearing on search results on Google, AdWords advertisers are automatically eligible to have their campaigns with keywords appear on the Google Network.
The Google Search Network
Ads are targeted based on a user's search terms. For example, if someone searches for "Italian coffee" on a search engine powered by Google, such as AOL.com, the user will see related coffee ads next to, above, or below search results, or on pages related to the user's search.
The Google Display Network
Text, image, video, or rich media ads are targeted based on themes in your keyword list, rather than specific keywords. You can target websites that have partnered with Google (display partners), YouTube, and specific Google properties.
You can learn more about the Google Display Network and watch the following video: