- On targeted topics and affinity audiences
- Only on targeted topics
- Only on targeted affinity audiences
- Only when targeted topics and affinity audiences match
Explanation: If we use affinity audience, the ad may be shown to the visitor, having immense interest in our product. In this case the can be shown on the pages irrelevant to our keyword, because we are targeting the audience. The audience who has seen the relevant pages earlier and shown the interest to similar products. That is why they are being added in affinity audience. Now, when we target topics, the ad will be shown on the relevant pages. Because we are targeting topics, that are associated with page.
Read more here (about the definitions only): https://support.google.com/partners/answer/2454017?hl=en