What is a session and how to start a session in PHP?

A session in PHP is a way to preserve data across subsequent HTTP requests. It allows information like user authentication status or user preferences to be stored and accessed throughout a user’s interaction with a website.

Starting a Session:

To start a session in PHP, use the session_start() function at the beginning of your PHP script. This function initializes a session or resumes the current one if it already exists.

<?php
session_start();
// Session started
?>

Destroying Complete Session

The session_destroy() function is used to destroy a session. The session_destroy() function does not require any argument.

<?php 
// session started
session_start( );        
// session destroyed 
session_destroy( );   
?> 

Important Points:

• Session Persistence: Once a session is started, PHP assigns a unique session ID to the user, which is typically stored in a cookie or passed through URLs. This ID allows PHP to associate subsequent requests from the same user with the same session data.
• Session Data: Session data is stored on the server side by default, typically in files or a database. It can hold various types of data, including variables, arrays, or objects.
• Ending a Session: To end a session, use the session_destroy() function. This function removes all session data associated with the current session, effectively ending the session.