What role does the .htaccess file play in directing URL requests to a central index.php file in PHP?

The .htaccess file plays a crucial role in directing URL requests to a central index.php file in PHP by using mod_rewrite rules to redirect all requests to the index.php file. This allows the index.php file to handle all incoming requests and route them to the appropriate controllers or actions within the PHP application.

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?url=$1 [QSA,L]