I found this:
Sponsored Product AdsIf you want to show up in Amazon’s search results for a particular keyword, you should choose a sponsored product ad. If, for example, you choose the keyword ‘gardening book’, and someone searches for this phrase, they may see your ad alongside the other search results.
This type of ad is a great way of attracting the attention of people who your book would be suitable for, but who wouldn’t otherwise come across it.
Product Display Ads.If you’d rather your ad shows up for a particular product, rather than in the search results for a keyword, you should choose a product display ad.
Amazon allows you to specify particular products, or particular types of products, that your ad will show up alongside. If you know you offer a superior version of a competing book, you can advertise in this way to persuade buyers to choose your title instead of, or along with, their original search.
Now that you know the way that AMS operates, and the basic types of ads you can choose...
Link To Article:
https://self-publishingschool.com/kindle-advertising-101/#types/Cheers,
R. C.