The Insights resource provides a single, consistent interface to retrieve ad statistics. Use this resource to measure the performance of your ads, ad sets, and campaigns. You can also make use of it for ads reporting and analytics needs.
The Ads resource represents the Ad object of Facebook's Marketing API. An ad object contains the data necessary to visually display an ad and associate it with a corresponding ad set.
The Adsets resource represents the Ad Set object of Facebook's Marketing API. An ad set is a group of ads that share one or more of the same denominators. It enables you to group ads and retrieve their related.