...Sites created in Wamp.NET are completely independent from Webserver and PHP version. You can change the assigned webserver and PHP version without affecting the vhost configuration or files and folders in the document root.
If you're coming from another **mp stack where you were limited to a single webserver, database and PHP version but want the features of Wamp.NET, you can of course mimic the same setup by only installing a single webserver, database server and PHP version for all your websites to use.