Codex confusion regarding home.php vs front-page.php

in the codex Theme Handbook it states that

If front-page.php exists, it will override the home.php template.

I had assumed that this meant that it will override it in all situations. However, it seems that if your blog index page is not set to be the homepage, the blog index page will use home.php as a template, even though front-page.php exists, and front-page.php will be used as a template for the front-page. This is totally not obvious to a beginner!