The kind of ad format that your site requested to be displayed, e.g., Display, Link unit, etc. This breakdown shows the formats you configured your site to request.
Depending on your ad setup, there might be different types of ads served within the requested format. For example, let's say that you've set up an ad unit to request display ads. Your ad unit might show different types of display ad such as animated image, HTML5, etc. Take a look at the Served creatives report to see a detailed breakdown of the ads that actually served on your site.
- Link unit