Google AdWords has two main types of targeting: Search Targeting and Display Targeting.
Search Targeting is based on the keyword model described above. Display Targeting (formerly known as the Content Network) is part of the Google Network. The Google Display Network consists of a group of more than a million websites, videos, and apps where your ads can appear. Your ads can be automatically matched to websites and other placements like mobile phone apps, when your ads and landing pages are related to the sites' content. You can also choose to target specific sites, pages about specific topics, demographic groups, and more.
The Display Network
The Display Network is a collection of websites -- including specific Google websites like Google Finance, Gmail, Blogger, and YouTube -- that show AdWords ads. This network also includes mobile sites and apps.
When showing ads on the Display Network, you can reach a wide range of customers with broad interests, choose which sites or pages to appear on, and engage users with appealing ad formats.
How can Display Targeting help you?
Reach new customers: Capture someone's attention at different points in the buying cycle. For example, if you run an art supply store, you can catch a mom's eye when she's reading reviews about the best brands of washable paints, but before she puts her toddler in the car seat and heads out to buy.
Select where your ads appear: Within the Display Network, you can choose more specifically where you want your ads to appear -- you can select types of pages or specific websites for your ads, as well as audiences to show your ads to.