You'd want to use is_home() when you want to check if the user is viewing your list of blog posts (usually set to display 10 posts per page). If you have a home.php file in your theme, that will be displayed when the is_home() condition is true.
The following can possibly remove some confusion as well: when is_front_page() and is_home() conditions, both are true, the template front-page.php will be used instead of home.php.
