Customize Reading Settings

/wp-admin/options-reading.php

Is this where the blog posts are controlled?

I am looking for the actual file that controls the formatting of the “Posts Page”

your theme’s single.php controls single post views
page.php controls page views
theme’s index.php controls front page

however, formatting is usually achieved by the theme’s style.css

Thanks for the help Sam. My questions is obviously unclear. I understand the CSS and pages you listed.

I have a static blog page that I have the Reading Settings>Front page displays>static page>posts page pointing to: have a look The page that controls this loop from the “Reading Settings” is what I am looking for.

Thanks!