session_start(); if (!isset($_SESSION['username']) || $_SESSION['role'] !== 'admin') { header('Location: login.php'); exit(); }In this example, the function is used to check if the user's session contains a 'username' key and if their 'role' is 'admin'. If these conditions are not met, the user is redirected to the login page. Session checkRight is not a package or library, but rather a built-in function in PHP. It is commonly used in conjunction with other PHP functions related to session management, such as session_start(), session_destroy(), and session_unset().