clarification php.fpm ini directives

Hello guys I have a request for clarification. After reading the documentation, I would like to outline how the override of the ini directives in php works. i use php-fpm Ini_se t> php_value > LOCAL > GLOBAL php_admin_value > ini_set > LOCAL > GLOBAL is it correct? are there exceptions? also i have no clear difference between php.ini and .user.ini thank you so much