How can PHP configuration settings, such as file_uploads and upload_max_filesize, impact file upload functionality on different server environments?

PHP configuration settings like file_uploads and upload_max_filesize can impact file upload functionality by determining whether files can be uploaded and the maximum size allowed for uploads. If these settings are not properly configured, users may encounter errors when trying to upload files. To resolve this, ensure that file_uploads is set to On and upload_max_filesize is set to a value that accommodates the desired file sizes.

// Ensure file uploads are enabled
ini_set('file_uploads', 'On');

// Set maximum file upload size to 10MB
ini_set('upload_max_filesize', '10M');