You need a web server like Apache, but for development you can use PHP's built in web server.
You should configure your web server so that it sends all appropriate requests to one front-end-controller PHP file.
Your application executes via this PHP file.
HTTP requests are re-routed within the app to controllers and controller functions - and here you create the logic of your application.
PHP's built in server:
a default controller to overwrite the build in controller