Yes, Cathy, that is correct. If someone puts a magnet in place of the magnet on your window, the security system will not go off when the window opens. The home security systems are really just there to keep out common thiefs and not professionals. But you can try it for yourself. If you look on your window or door you'll see a small rectangular plastic thing and adjacent to it on the window frame is another similar thing but it has wires going to it. The one on the door or window is actually a magnet. The one on the frame is a switch that is magnetically controlled. Open your window and look at your control panel for your security system and you'll see the light go on that one of the windows/doors is open. Now take one of the refrigerator magnets and put it near the switch on the frame. If you have it close enough you'll see the light on the control panel go out indicating the window/door is now closed again.