> The unwashed masses say SCADA. Those in the know say Industrial Control Systems. At least that's what I'm told. I'm kind of the unwashed type myself.

The terms are often interchanged, even if they shouldn't be. "SCADA" (Supervisory Control And Data Acquisition) is your secondary control and historian/logging system, and will often be in control of sending data across comms links and monitoring events. An ICS (Industrial Control System) is your front-line system in charge of controlling your valves, motors and equipment directly.

The roles have become more blurred together, especially as we move towards more general-purpose equipment and IP-based networks.