Integrated Web sites and front-end
ServiceNow, as an enterprise cloud platform, allows you to use it just as a back-end, so any web site can be used as a front-end to communicate with ServiceNow - seamless data transfers to/from ServiceNow, ticket/requests submissions etc.
That means you may have your personal web portal with custom web design, graphics and forms, which is closely integrated with your ServiceNow instance.
This is the case when you have one or multiple existing web sites and want to integrate them with ServiceNow.