session_start(); echo "Welcome, ".$_SESSION['username'];
if($_SESSION['user_role'] == 'admin'){ // show admin-only content } else { // redirect to login page or show error message }This code checks the user's role (Admin or not) and shows/hides content based on that role. Package Library: Some popular PHP libraries for user authentication and access control include PHP_AUTH, Sentry, and Laravel's User Authentication.