The port number assigned to the default SharePoint Web Application. If not specified, then port 80 is used. If a SharePoint ...

The port number assigned to the default SharePoint Web Application.  If not specified, then port 80 is used.  If a SharePoint Web Application already exists using the port, the existing site will be overwritten.  If an existing site is using the port and is not a SharePoint Web Application, the site will be disabled and a new SharePoint Web Application will be created using the port.