Control Panel: The central hub (or "brain") that processes signals from all connected devices and manages arming or disarming.Sensors and Detectors: Devices like door/window contacts, motion sensors, and glass-break detectors that identify physical breaches.Sirens and Sounders: Loud internal or external audible devices meant to alert neighbors and scare away intruders.Keypads or Key Fobs: Interfaces used to input passcodes to set or unset the system.