Service post is a page. It is a list of 4-7 or more services related to the niche but not enough searches to rank.
Pest control niche service posts would be links to a rat page, a spider page, etc.. Video 0 excercises will show you all services in your niche.
A post is a like blog post just topics related to your niche.
All of our sites in module three have sample service posts.