Do I need lighting bridge?

I can't find a clear answer to this question. There's a statement in the answers that says, " it is at the center of your setup connecting lights, Motion Sensors, and Transformers together", but I have light switches, the outdoor spot-cam, motion sensors now, and they seem to connect together, and I only have the base station. I'm just not clear on what the bridge does that the base does not. At this point I have: controller, co/smoke alarms, keypads, ge smartswitch controlling lights, range extender, door/window sensors, garage door sensor, motion detectors, floodlight camera, wired cameras and front door keypad. Can you tell me what capabilites I'd add by adding the bridge?