Google Display Advertising(GDN)
The GDN is managed within the AdWords interface. Targeting on the GDN can be done either contextually or with placements. Contextual targeting will allow you to find sites that are relevant in content based on the keywords you select. For example, if you are selling sports equipment, an ESPN article on sports is where you can show a display ad on the GDN.
You can also be very specific and place media buys on specific sites using Google’s placements technology whereby you select specific sites to publish your advertisements. Over the years, Google has invested significantly in their research and development to increase their targeting and retargeting capabilities. There have been significant improvements to the levels of sophistication on the GDN for contextual, placement and retargeting