The part of the ICS used to perform the monitoring and control of the physical process. This includes all control servers, field devices, actuators, sensors, and their supporting communication systems.
NIST SP 800-82 Rev. 2 under Control
the Control phase consists of managing investments while monitoring for results. Once the IT projects have been selected, senior executives periodically assess the progress of the projects against their projected cost, scheduled milestones, and expected mission benefits.
NIST SP 800-65 under Control
measure that is modifying risk. (Note: controls include any process, policy, device, practice, or other actions which modify risk.)