How can session.save_path in the php.ini file affect the functionality of PHP sessions?

The session.save_path in the php.ini file specifies the directory where PHP stores session data. If this path is not set correctly or does not have the necessary permissions, it can cause issues with PHP sessions, such as sessions not being saved or retrieved properly. To solve this issue, ensure that the session.save_path in the php.ini file points to a valid directory with write permissions.

// Set the session save path in PHP code
ini_set('session.save_path', '/path/to/session/directory');

// Start the session
session_start();