What server settings in PHP may need to be adjusted to ensure successful file uploads from a client to the server?

To ensure successful file uploads from a client to the server in PHP, you may need to adjust the following server settings: `upload_max_filesize`, `post_max_size`, `max_input_time`, and `max_execution_time`. These settings control the maximum size of uploaded files, maximum size of POST data, maximum time allowed for input, and maximum time allowed for script execution, respectively. Adjusting these settings in your PHP configuration file can help prevent issues with file uploads.

ini_set('upload_max_filesize', '20M');
ini_set('post_max_size', '25M');
ini_set('max_input_time', 300);
ini_set('max_execution_time', 300);