A Guide to the Parts and Components of a Security System

Written by | Updated July 28, 2015

Parts and Components of a home security system

A security system utilizes a network of components to help keep your family and home secure. Each of these home security system parts plays a vital role in the overall protection of your home, with many of them working together to help keep you safe.

Not all security system parts are interchangeable, so it’s important you purchase them from your current security monitoring company, if you have one. Otherwise, check for compatibility when making the decision to add a new part to your home. Here are some of the most popular home security system components and what they do.

Control Panel

The control panel serves as the main hub for the security system. It’s usually a touchpad that allows you to enter passcodes for arming and disarming the system, and some have a voice control feature. The control panel communicates with other security system components, like motion sensors and cameras, and ensures they all work together. It also connects you directly to your alarm company’s monitoring system.

Home security control panel

Motion Sensors

Motion sensors detect when an intruder enters your home. They use vibration, ultrasonic waves, microwave pulses, infrared heat, or any combination of these to sense when someone is moving within your home or on your property. They’re essentially electronic watchdogs that notify your control panel when a breach occurs.

home security motion sensors


Security cameras come in wireless and wired versions and can be concealed both on the inside and outside of your home. These cameras capture motion and activity and many can send you the video feed to an accompanying app, giving you an eye on your home wherever you are. There are cameras that pan and tilt, static, or swivel, and you can get some that include night vision, all depending on your needs.

Home Security Cameras

Door and Window Sensors

These sensors notify you when a door or window is opened in your home. Sensors are placed on the door or window and on the adjoining sill or frame. When closed, the sensors are touching and everything is noted as secure. Once the door or window is opened, it triggers the reed switch, a magnetic connector that can sense when the sensors are/aren’t touching, and alerts your control panel.

Window and door sensors

Carbon Monoxide Detector

Carbon monoxide detectors are usually placed outside the doors of sleeping areas and detect rises in the levels of carbon monoxide gas in the home. There are three types of detectors typically found with security systems, each of which will sound an alarm until the levels dissipate.

Biometric Sensors: contain a gel that changes color when absorbing carbon monoxide.
Metal Oxide Semi-Conductors: react to the gas by lowering the electrical resistance in the detector.
Electrochemical Sensors: detect changes in electric currents caused by carbon monoxide.

Cellular Backup Unit

A cellular backup unit provides an alternative method for your security system to notify the monitoring center of a break in should someone cut your system’s wires or your traditional infrastructure goes down. It works wirelessly, keeping you constantly connected to the center so they can detect any emergencies and send authorities if needed.

Electric Door Locks

Electric door locks provide you with a way to ensure your doors are locked at all times, even when you’re not home. Most modern security systems allow you to access these remotely through your smartphone. The system also tracks whether the door is locked and can notify when it is opened. These smart locks are a useful way to monitor the home when you’re at work or keep track of whether or not your children are locking the doors when they come and go.

Electric Door Lock

Yard Signs and Window Stickers

Signs and stickers displaying the name of your security system show potential thieves that your home is protected, thus helping deter them from attempting to enter your home. You place them prominently on windows or around the yard so they’re visible to potential intruders.

The idea is the signs will provide an invisible layer of protection by forcing a burglar to think twice before trying to step foot on your property. They also let your neighbors know you’re happy with your security system by displaying the name proudly on your property.

Fake Yard Signs Help Deter Burglars

Key Fob

The key fob is an alternative to the traditional touchpad used to arm and disarm your security system. Much like a remote car lock, it allows you to arm/disarm your security system before going through the door. Security providers can usually set up multiple key fobs for you and your family to keep around the home. You can use them to set the system before going to sleep at night or once you’re in your car leaving for work.

Panic Pendant

A panic pendant is a small device worn on the user and provides direct and immediate access to security specialists at the monitoring company. When the pendant is triggered, a security expert is notified and will respond to determine if you’re in need of assistance. The monitoring center representative can then remotely send emergency personnel to help, if needed, whatever the situation may be.

High-Decibel Alarm

If someone is breaking into your home, you want your alarm to be loud enough for people to hear it. Not only can this help notify your neighbors and emergency responders of the intrusion, it could help drive the intruder away from your home. The high-decibel alarm is loud enough for everyone in the home to hear, as well as the surrounding neighborhood.

A home security system is at its best when it has all the available tools ready to help monitor your home. When faced with an emergency, don’t be left without a crucial element of a security system that could’ve added that extra layer of protection.

Written by Hillary Johnston

A proud mother of four, Hillary is passionate about safety education. She holds a degree in Public Health and Disaster Management. Learn more

Share this article.