In this example, we are setting two session variables 'username' and 'email' with the values 'John' and 'john@example.com' respectively. Example 2:php 'John', 'email' => 'john@example.com']; $_SESSION['user'] = $user; ?> ``` In this example, we are setting a session variable 'user' which is an array having two key-value pairs. The package library used for the PHP session functions is 'session'. It is a built-in extension that provides session handling functionality for PHP. It is always available in PHP and there is no need to install it separately. The session library provides various functions to manage the sessions such as session_start(), session_destroy(), session_unset(), etc.