What is the significance of the php.ini file in relation to file upload size restrictions in PHP?

The php.ini file is significant in setting file upload size restrictions in PHP as it allows developers to configure the maximum size of files that can be uploaded to a server. To increase the file upload size limit, developers can edit the "upload_max_filesize" and "post_max_size" directives in the php.ini file.

// Increase file upload size limit in php.ini
ini_set('upload_max_filesize', '20M');
ini_set('post_max_size', '25M');