Service Portal lets you create a custom interface that builds over existing data and logic. All of the chapters so far have concentrated on building, configuring, or customizing application logic-Service Portal allows you to change how it looks so that you move away from plain forms and lists.
This means that Service Portal should not generally bring any new functionality to your application. Instead, the creation of a portal is intended to provide a new way for requesters to access capability that has already been built. The Hotel application for Gardiner Hotels includes a way to raise maintenance tasks and create reservations. Wouldn't it be great if the hotel guests could do this themselves, if they wanted to?