What is session in php? how can use the php session?

What is Session:- 
A php Session variable  is stored the single user information and are available all the page in the application.

A PHP session solves this problem by allowing you to store single user informations on the server at a time.session information is the temporary store on the server,you are left the site then will be deleted.

Session work on a unique ID because they are stored single unique value on the server. 

Starting a php session-
                                                   <?php
                                                                start_session(); // session is start
                                                       ?>

A simple Example describes below for using php session on a  page-

session.php

<?php

  session_start();

//session initialization 

  $_SESSION['view'] = 'rajendra'; // storing session (value rajendra) * view is session name this is optional if you want then change the name

  

?>

<?php

    echo "welcome " . $_SESSION['view'] . "<br/>"; 

// print the session value welcome  rajendra

?>

<?php

    if(isset($_SESSION['view']))

    {

        echo "Session is set..."; // session have a value then session is set 

    }

    else

    {

        echo "Session not set...";

    }

?>

<?php

    unset($_SESSION['view']); // unset the session value because session is logout

    session_destroy(); // delete all information of the session called session_destroy

    echo "session destroy...";

?>