Unlike some years ago when websites were almost exclusively static, the standard today is to have a feature-rich, dynamic website. Not everybody can build this kind of web site completely from scratch though, so the simplest solution to have a dynamic site is to use a script application. A lot of web hosting service providers offer script installers which can be used to add this kind of an app for any of your domain name or subdomains, so you'll not need to add anything manually. The main advantage of using an installer tool would be that the scripts are ready to use in a couple of minutes and the copy that'll be installed is already with the settings required for it to run the way it should on the specific hosting web server, so you'll not have to adjust any script or account settings. That way you can quickly create one with just a couple of clicks even if you have never had a site before.