What is a weak current system for monitoring and alarming?

Weak current systems, including network, telephone, satellite TV, cable TV, integrated wiring, video sharing, security alarm, video monitoring, access control system, etc., all belong to weak current systems. Then what you said, surveillance alarm is video surveillance, which is what we often see. In some communities, the monitoring system of traffic intersections mainly includes host, camera, monitor, power supply and a monitoring system connected to the host through power lines and video lines. Alarm systems, mainly indoor security detectors, are generally installed in windows and doors and protected by keys. When someone opens the doors and windows, the detector will sound through the sound and light alarm once it detects someone. This is probably such a system. I wonder if you can understand my answer like this.