The web content server is a web application that forms the interface between the Silverlight Applications (hosted in SharePoint) and the Service Manager management server. It provides a path for data from the Service Manager management server to the Silverlight
applications running in the browser. You will need it in order to run your web portal. You can run them both on the same server if necessary.
It is also important to not that you want to use the same protocol for the web content server and the SharePoint website (they both must be https:// or http://)