How can .htaccess be used to configure upload size on a web server?

To configure upload size on a web server using .htaccess, you can set the values for the PHP directives `upload_max_filesize` and `post_max_size`. This can be done by adding the following lines to your .htaccess file: ```apache php_value upload_max_filesize 20M php_value post_max_size 25M ```