监控 (jiān kòng) means 'to monitor' using electronic or technical systems (cameras, sensors, software), often with the ability to respond or control. It differs from 监督 (jiān dū) 'supervise people/processes', 监测 (jiān cè) 'continuously measure data', and 监视 (jiān shì) 'keep a close watch on persons'. 监控 implies a systematic, often automated surveillance with a control component.