You can use SESSIONS to store persistent user preferences on your Website. Each session has a data store related to it and its content persists between pages.

To start using a session you need to call session_start(), but you have to remember:

• you can call session_start() just once per file
• you need to call it before the script generates any output (before you send any data to the browser)

Session_start() will load session data in the $_SESSION associative array.

The easiest way to store data in a session is:

$_SESSION['name'] = “value”;

Here a simple example about how to use $_SESSION:

<?php 
    //starting a  session
    session_start();

    //checking if session data about visits exists
    if( isset($_SESSION['visits']) ){
        //incrementing visits counter
        $_SESSION['visits'] = $_SESSION['visits'] +1;    
    } else {
       //creating a visits variable in session 
       $_SESSION['visits'] = 1;
    }
    
    
    //accessing data from session
    echo "<p>You have been here <strong>" .$_SESSION['visits']. "</strong> times.</p>"
 ?>

To end a session, you can use session_destroy()