What is the use of global variables in php declarations outside of functions?

What is the use of php to declare global variables outside the function? What is the use of php to declare global variables outside the function? I see this section in the wordpress wp-settings.php File: * & nbsp; These & nbsp; cant & nbsp; be & nbsp; directly & nbsp; globalized & nbsp; in & nbsp; version. php. & what is the use of nb php to declare global variables outside the function?
What is the use of php to declare global variables outside the function?

I see the following section in the wordpress wp-settings.php file:

/*
 * These can't be directly globalized in version.php. When updating,
 * we're including version.php from another install and don't want
 * these values to be overridden if already set.
 */
global $wp_version, $wp_db_version, $tinymce_version, $required_php_version, $required_mysql_version;
require( ABSPATH . WPINC . '/version.php' );

Sorry, please explain. thank you! ^_^
------ Solution --------------------
No effect
And not seen in wp-settings.php
Global $ wp_version, $ wp_db_version, $ tinymce_version, $ required_php_version, $ required_mysql_version;
Only
Require (ABSPATH. WPINC. '/version. php ');
------ Solution --------------------
No effect