A closer look at how common security components work
Control panel
The control panel is the computer that arms and disarms the security systems, communicates with each installed component, sounds the alarm when a security zone is breached, and communicates with an alarm monitoring company.
They typically feature a touchpad for easy programming and interaction. You'll enter your PIN to arm and disarm the system, but some can be armed with a voice command. You can also use a key fob to arm and disarm the system quickly, or use a smartphone app to control the system from anywhere in the world—literally.
Door and window sensors
Door and window sensors—also called contact or entry sensors—are comprised of two parts. They're installed right next to each other on a closed door and door frame (or closed window and window frame). One part of the sensor detects a magnet in the second part. As soon as the magnet is moved out of range (i.e., the door or window opens), the sensor communicates a breach to the control panel.
Motion sensors
When armed, motion sensors protect a given space by creating an invisible zone that cannot be breached without sounding an alarm. Common motion sensor technology includes ultrasonic waves and passive infrared technology.
Motion sensors are typically used to protect hallways, rooms with multiple windows or entry points, and areas with an open floor plan.
Glass break sensors
Glass break sensors protect rooms with multiple windows. They work by sensing either the vibration or sound of breaking glass. Sound-based glass break sensors are more common.
Security cameras
Available in both wired and wireless configurations, the typical home security camera only records footage when motion is detected.
Most home security cameras connect to a smartphone app via Wi-Fi so you can view live footage at any time. Recorded footage is stored in the cloud or on a microSD card.