The Internet Display Client is a runtime-only version of CitectSCADA. An Internet Display Client cannot be a server, and it cannot be used to make configuration changes - you can only run your project.
A computer can have a normal CitectSCADA installation as well as the Internet Display Client. Before you can run a project over the Internet, you need to switch the [Internet]Client parameter on.
You can also run multiple instances of the Internet Display Client at the same time. This allows you to work with more than one project, in runtime-only mode, on the remote computer.