How can the session_id affect the transfer of sessions in PHP?

The session_id in PHP is used to uniquely identify a user's session. If the session_id is not properly transferred between pages or stored correctly, it can lead to session data being lost or mixed up. To ensure smooth transfer of sessions, it is important to properly set and retrieve the session_id in each page of the application.

// Start the session
session_start();

// Set the session_id to be transferred between pages
$session_id = session_id();

// Use the session_id to retrieve the session data
session_id($session_id);