Are the ads in Facebook considered as posts , is there a way to distinguish organic posts from Ads ?
Some type of ads like unpublished page posts are ads considered "posts".
Usually, non-serving posts on the Page are used to create ads in the News Feed that will not appear on your Page.
Visually, in the news feed, you see as "sponsored post".
Using the API (https://developers.facebook.com/docs/graph-api/reference/v2.9/post), you can distinguish the posts using the field "is_published", that returns 'false' for page posts created as part of the Ad Creation process.
I hope it helped you.