Home Security Systems and Security Cameras: A Glossary of Terms

by Deep Sentinel | | Learning Center

Home security systems and security camera specifications can be confusing. We've created these definitions of commonly used terms with our customers in mind, to take the confusion out of the shopping and decision-making process.

1080p

This describes how many pixels are in the digital video, the full expression being 1920 x 1080, width x height. The more pixels, the higher the resolution and the greater the video detail, although there are many other factors affecting video quality. 1080p is equivalent to the term Full HD, and is about twice the resolution as standard HD. There is a noticeable improvement between the two. Blu-Rays are Full HD while DVDs are HD. Resolutions greater than 1080p are virtually unnoticeable unless projected on a very, very large screen, or when digitally zooming in.

2-Way Audio

Security cameras are said to have 2-way audio when they have both a speaker and a microphone built into the camera. This allows for the user to speak to people near the camera through their mobile app, and hear the response. This is useful for updating couriers or checking in with family and caregivers, as well as communicating with potential intruders they are being watched and the police are on their way.

2.4GHz / 5GHz Network

WiFi uses radio waves in either the 2.4GHz or 5GHz frequency bands. 2.4GHz is the universal WiFi band and all wireless security cameras can use it. If the home router or hub supports a 5GHz channel, then the camera can send across that network, which technically has faster speeds than a 2.4GHz channel, meaning the footage can be of higher quality. However, 5GHz channels have a much more limited range, meaning outdoor security cameras are less likely to maintain a good connection and will likely see a quality reduction.

720p

This describes how many pixels are in the digital video, the full expression being 1280 x 720, width x height. The more pixels, the higher the resolution and the greater the quality, although there are many other factors affecting video quality. 720p is equivalent to the term standard HD, and is about half the resolution of Full HD. There is a noticeable improvement between the two. When a product is marketed as HD, it will often be 720p.

802.11

If examining the spec line of security cameras closely, this number appears next to Wireless cameras under WiFi connectivity. IEEE 802.11 is the frequency standard used by wireless technology for sending information across their network. There have been improvements within this standard, from oldest to newest being: a, b, g, n, ac. Many security cameras can use multiple standards, and may show something like this: 802.11 b/g/n.

Activity Zones 

See motion zones.

AI Technology

This stands for Artificial Intelligence. Security cameras equipped with this technology can learn from mistakes, such as when the user identifies an alert as a false alarm. The security camera will then adapt and become less likely to send an alert when a similar  motion event occurs. Less false alerts means less useless interruptions, and more trust in the system.

Alarm 

An alarm is how the security system reacts when it is triggered. Many alarms have two stages: notification and signal. In the notification stage, the security system alerts either the owner or the monitoring center that a breach has occured. In the signal stage, the person or people notified respond by activating sirens, flashing lights, and / or speaking through a microphone to the culprit, depending on what the security system is capable of doing. Some security systems do not notify and simply activate sirens and / or lights when triggered.

Alerts

An alert is the security system informing the owner or monitoring center that a breach has occured. This can be done through notifications sent to the owner’s mobile or monitoring center’s computers. Often it will describe which security device was triggered, such as a motion event in a security camera or a door sensor tripping.  If there are security cameras equipped, the owner and monitoring center can check to make certain that this is a serious situation and not a false alarm.

Armed

Security sensors can be armed or disarmed, meaning turned on or off. There are times of day when the owner or their relatives/friends are home, and don’t want to be constantly alerted about movement or the opening of doors. Security systems offer the ability to disarm the detection for such cases.

All-In-One Device

An all-in-one device is a marketing term used to describe a single product that provides an array of security features. At minimum, this includes a camera with motion sensing capabilities, a siren, 2-way audio, and an app that allows the user to watch footage and activate the product’s features from anywhere.

Analog Camera

The original way security cameras transmitted image data was as varying voltages through BNC (Bayonet Neill–Concelman) cables. Analog security cameras are still around, largely because they’re difficult to hack, lots of places already have the wires in place, and technical improvement have let them reproduce digital HD resolutions. There were many analog technologies competing for HD resolution, but it appears the winner is HD-TVI. Analog cameras can connect to a DVR to be viewed and saved as digital files.

Audio Alerts

An audio alert is a notification sent out to the owner or monitoring center that the audio sensor has detected a sound that it thinks indicates a suspicious activity. This is an uncommon feature in security systems outside of glass break sensors, as motion detection has proved more reliable than audio detection in catching suspicious activity. However, some security cameras do provide audio sensors and alerts, with adjustable sensitivity sliders.

Audio Detection

Audio detection is when a security system can use sound as a means to trigger its alarm. When a sound meets the programmed requirements to be considered suspicious, the security system sends the owner or monitoring center an audio alert. This is an uncommon feature in security systems outside of glass break sensors, as motion detection has proved more reliable than audio detection in catching suspicious activity. However, some security cameras do provide audio sensors and alerts, with adjustable sensitivity sliders.

Audio Sensor

An audio sensor is a piece of hardware designed to detect sounds of intrusion. If it detects a sound that meets the programmed requirements to be considered suspicious, the security system sends the owner or monitoring center an audio alert. This is an uncommon feature in security systems outside of glass break sensors, as motion detection has proved more reliable than audio detection in catching suspicious activity. However, some security cameras do provide audio sensors and alerts, with adjustable sensitivity sliders.

Base Unit

See Central Hub.

Battery-Powered

A battery-powered security camera will operate without needing access to an outlet and without needing a wire to run to the outlet. Security cameras that are solely battery-powered use WiFi as well, so that they can benefit from an entirely wire-free system and can be placed anywhere with an easy, do-it-yourself installation. Some security cameras use batteries, but only as a backup source of power in case of a power outage or if the lines are cut. Security cameras that are not battery-powered may still use WiFi but need an electrical line, may be PoE cameras so use one cable, or may require two cables, one for electricity and one for sending video footage, such as analog cameras.

Box Camera

This describe a certain uncommon shape of security camera. Box cameras are rectangular and, unlike most other security cameras, use interchangeable, varifocal lenses that can optically zoom in and out. The zoom can be controlled remotely. Other camera shapes include bullet and dome.

Break-In

A break-in is whenever a person enters, by whatever means, into someone else’s house without consent or legal permission, and with criminal intent. For instance, someone walking through an unlocked front door and stealing a TV is a break-in. A neighbor who breaks in to help someone in an emergency is not committing a break-in.

Bullet Camera

This describes a certain very common shape of security camera. Bullet cameras are built much longer than wider, and thus look a bit like a bullet. The mount is attached to one end and the camera lens built into the other. Another name for security cameras of this shape is lipstick cameras. Other camera shapes include dome and box.

CCTV Camera

This stands for Closed-Circuit Television. It simply means that a camera sends its footage to a limited and private number of locations. Virtually all surveillance camera systems fall under this category, although it’s often used to describe security systems where the cameras are wired, transmit to a DVR, and project to a security monitor or monitors.

Central Hub

Many security systems and smart home systems have a central hub. This is the device that connects all the various security and home automation devices together and communicates across them. There can be a control panel, mobile app, and / or a voice-activated personal assistant like Alexa that communicates with the hub that let’s the user control their security and smart home system. Note that there are many security and home automation devices that can only connect to certain central hubs.

Cloud Storage

Cloud storage is when files are not saved on the user’s own computer or mass storage device, but on a remote storage device, typically a massive server system somewhere, which they don’t own and have limited permission to use. Typically, security cameras that send the video footage they record into cloud storage charge a monthly fee for this, and have price tiers with various add-ons for buying the more expensive subscription. Many of these cameras don’t provide the option of local storage of security footage. When cameras don’t use cloud storage they use local storage, often through a DVR , NVR, or central hub.

Charging Station

This is used to charge rechargeable batteries. Many security cameras use specially designed rechargeable batteries that won’t fit into any charging station but the one that is specifically made for the product.

Continuous Video Recording (CVR)

This is a feature that lets the security camera record 24/7, or until you program it to stop. It is only available on some cameras. No security cameras have this feature available when battery-powered because recording is what quickly drains battery life. CVR is rarely used in outdoor cameras, because a tremendous percentage of the footage would be of nothing. For indoor security cameras, it’s often marketed as beneficial for watching over children, pets, or the elderly.

Control Panel

Many security systems come with a control panel that is separate from the central hub, although some also serve as the central hub. The control panel is where the user can interact with the security and / or home automation system and make changes to it. Other ways to interact with the security and home automation system is through the central hub’s mobile app, if it has one, or through a voice-activated personal assistant like Alexa, Google, and Siri, if the central hub is compatible with them.

CVR

See Continuous Video Recording.

Digital Video Recorder (DVR)

Often abbreviated to DVR. DVRs made for security systems are often used with analog cameras to turn the TV signals into a digital signal and store the footage locally, but can be used with IP cameras to store the footage as well. A computer and / or monitor is attached to the DVR to let users control the security system and to watch live or saved footage. Many modern DVRs also have a mobile app, can perform motion detection analytics for the security cameras, and can alert the user when it detects something suspicious. DVRs only work with security cameras that are physically wired to it with BNC cabling, whereas NVRs can work with wireless or PoE cameras.

Digital Zoom

Most home security cameras are not equipped with varifocal lenses that optically zoom in and out. Instead, they have digital zoom, where the camera records only part of the image that its image sensor sees. For instance, 4x zoom means the camera can digitally zoom in on one quarter of its image sensor and show just that. This does mean there is resolution loss when digitally zoomed in. The more megapixels your security camera’s image sensor has the less this loss will be noticeable. Stay digitally zoomed out when recording for best quality.

Disarm

See Armed.

Do-It-Yourself or DIY

Often abbreviated to DIY. This means that the security system is simple enough for self-installation and oftentimes means that there is the option to self-monitor as well. Marketers will generally use this word when their product is wireless or wire-free, or when they don’t offer professional monitoring.

Dome Camera

This describes a certain common shape of security camera. Dome cameras are built in the shape the name implies, often with glass or clear plastic compromising a large part of the dome. The lens is behind the glass, and can be remotely told to swivel around to view different angles. Other camera shapes include bullet and box.

Door Sensors

A door sensor is a security device that gets placed on the edge of a door. It is designed in two pieces, when they are pulled apart, the device sends a signal to the central hub that is has been triggered. The hub then alerts the user or monitoring center that a breach has occurred. Door sensors can be purchased by themselves, but will not work without a central hub. Not all door sensors work with all hubs so double check compatibility. Be sure to arm the door sensor or it will not trigger. Without security cameras pointed at the scene, the owner and monitoring center won’t know for sure if it’s a false alarm.

DVR

See Digital Video Recorder.

Ethernet

Ethernet is a means of digital data sharing, and is used in many security systems to connect sensors and security cameras to an NVR, or to connect the DVR, NVR or central hub to the router. Connecting these systems to the router via an ethernet cable will connect them to the internet, and, because it’s a physical connection, generally give much higher transfer speeds than is achievable over WiFi. Ethernet cables can go hundreds of feet before they see any data speed loss. CAT5, CAT5e, and CAT6 are cabling varieties most often used with the ethernet standard, and all support PoE.

Facial Recognition

Some security cameras support facial recognition features. After motion has been detected, these cameras analyze the individual’s face and attempt to make a match. If a match is made, an alert is sent out saying who is on the premise. If a match isn’t made, an alert is sent out saying no match was made, and the user can input who it is or sound the alarm. Facial recognition requires a degree of AI technology, so that it can learn new faces and attempt to detect these faces under a variety of conditions. Facial recognition software in home security systems is currently quite limited but undergoing advancement. A lot of facial recognition is cloud-based, meaning powerful remote computers are analyzing the faces instead of the security system at home.

Field of View or Field of Vision (FOV)

This is how far to the left and right the image sensor can capture, measured in degrees. On average the human eye has a FOV of 220 degrees, which is far greater than any home security camera can or should see. Past 140 degrees, objects on screen will appear warped and increasingly hard to identify, because they’re being compressed onto a 2D screen from a very 3D view of the world. This is why security cameras aren’t competing to have the highest field of view.

Fixed Lens 

A fixed lens is a camera lens that cannot optically zoom, and therefore has a locked field of view. Most security cameras use fixed lenses because they are cheaper and more easily avoid losing focus. In the security camera field, zoom lenses are called varifocal lenses.

FOV

See Field of View.

FPS

Stands for Frames Per Second.

Frame Rate or Frames Per Second (FPS)

Video is essentially just many images passing so quickly that they are seen as steady motion. Frame rate is how many images are captured per second and recorded as a video. In U.S. cinema, the standard is 24fps (frames-per-second). In U.S. reality TV, home video, and security footage, the standard is 30fps. Many security cameras will have a lower frame rate when night vision is on, because there is less light in the scene and a lower frame rate will let more light into each individual image.

Full HD

This stands for Full High Definition, and is a term used to describe the resolution of a video. The greater the resolution, the more detail in the image, although there are many other factors affecting video quality. Standard HD is 1280 pixels wide by 720 pixels tall, and about half the resolution of Full HD, which is 1920 pixels wide by 1080 pixels tall. DVDs play in HD, while Blu-Rays play in Full HD.

Glass Break Sensor

A glass break sensor is a security device that gets placed near a window or glass sliding door. It is an audio sensor that specifically listens for the unique sound pattern of breaking glass. If a burglar ever breaks in through the window, the glass break sensor will trigger and inform the central hub, which will send an alert out to the owner or monitoring center. Glass break sensors can be purchased by themselves, but will not work without a central hub. Not all glass break sensors work with all hubs, so double check compatibility. Usually the glass break sensor cannot be disarmed, because there’s virtually no reason to do so.

HD

This stands for High Definition, and is a term used to describe the resolution of a video. Although both 720p (standard HD) and 1080p (Full HD) are technically High Definition, the term HD in marketing is usually given to home security cameras that record only standard HD.

HD-TVI Camera

This stands for High Definition Transport Video Interface. It’s replacing traditional analog security cameras because it is backwards compatible with the complex analog wiring, and can send information at HD resolutions. It can also send this information at tremendous distances, over 1500ft, with insubstantial quality loss. Although HD-TVI cameras can be cheaper than IP cameras, professional and expensive installation is required, and improvements to IP cameras are coming much quicker.

Home Automation

Home automation is when various traditional household appliances are replaced with network-connected appliances. They can either work individually off their own mobile app or connect to a central hub, where the user can use a control panel, mobile app, or voice-activated personal assistant like Alexa to control the settings on the devices. When a home has a lot of automated devices, it is referred to as a smart home.

Home Security System

Home security systems are designed to protect the owner, their family, and belongings from the harms of home invasion. Security systems come in many shapes and forms: they can be as simple as an all-in-one device, or as comprehensive as a central hub with connected door, window, and motion sensors and security cameras. Nowadays, security systems either inform the owner through an alert to their mobile phone that a break-in has occurred, to which they can sound the alarm and call the authorities, or systems connect to a professional monitoring center, which handles the alarm and police response and informs the owner of what’s happening.

Hub

See Central Hub.

IFTTT

This stands for “IF This, Then That.” IFTTT is a software platform that allows programming between different apps for tight interconnectivity. Many smart home devices and some home security devices are compatible with IFTTT. A security system that connects to a sleep tracker, for example, can be programmed to disarm when the user wakes up. However, there are currently great concerns about security vulnerabilities when using IFTTT, so it’s recommended not to integrate the security system with non-security programs.

Indoor Camera

An indoor security camera is designed in such a way to render it inoperable if used outside the home. Most of the time, the camera’s casing is not weatherproof and has a low IP Rating. Indoor cameras are also much more likely to be wired, because outlets are readily available and cameras are capable of being built with more functionality when physically plugged in. Indoor cameras are not likely to prevent a break-in, because they are not a visible deterrent from the outside. However, they can be used to prevent greater theft if the owner or monitoring center sounds the alarm, and can be used to identify the criminals.

Infrared

Below the visible wavelength spectrum of light lies infrared light. Although humans can’t see it, technology is able to capture this light and use it to detect motion and analyze the heat of objects. Humans and other objects emit heat energy constantly, and this energy is in the infrared spectrum.

Infrared LEDs

Often abbreviated to IR LEDs. These LEDs emit infrared light, and are used by security cameras to give them night vision. Although security cameras flood the area in front of them with infrared light, humans can’t see it so nothing appears to be happening. Usually, IR LEDs are turned off during the day and are activated and deactivated by the IR Cutoff Filter. If they were left on, there would be color distortion during the day. This is also why night vision is generally shown in black and white. The most common infrared wavelength in LEDs is 850nm.

Installation

Security systems require installation. Traditionally, security systems required complex wiring and thus an electrician and other experts to come in and perform a professional installation. These systems are still available today in the form of analog and wired IP cameras. Nowadays, there are do-it-yourself security system installations that don’t require any wiring beyond perhaps plugging a cord into an outlet. Self-installations are far less expensive and destructive to the house, although having professionals around to help determine the best locations to place security devices can be beneficial.

IP Camera

This stands for Internet Protocol camera. Nowadays, most home security cameras are IP cameras, it simply means they are programmed to send information the same way it’s sent over the internet. This doesn’t necessarily mean they are connected to the internet, just that it’s the same method. IP cameras can send video information either through WiFi or an ethernet cable, although for marketing purposes it’s often used to describe cameras that transmit to a DVR or NVR using an ethernet cable. Non-IP cameras are called analog cameras.

IP Rating

The Ingress Protection Code is a standardized rating system for how well appliances deal with liquids and solids. Unlike words like weatherproof and water resistant, an IP rating means the product met certain protection requirements. The first number rates the appliance against solid objects while the second rates the appliance against liquids. An IP rating of 65 means the object is dust tight and cannot be harmed by particles of any size, and that jets of water against the object will have no effect. An IP of 66 means that powerful jets of water against the appliance will have no effect. Either is effective for outdoor security cameras.

IR Cutoff Filter

IR LEDs are necessary for night vision, but during the daytime IR LEDs would distort the colors on screen. The IR cutoff filter, also known as cut filter, senses brightness and activates the IR LEDs when it becomes dark out and turns them off when it becomes bright.     

IR LEDs

See Infrared LEDs.

Keypad

In security systems, a keypad is often used to arm and disarm the system. Many security systems only allow for a short amount of time after a sensor has been triggered to input the code into the keypad before the monitoring center calls to check in. If self-monitored, the owner will receive an alert immediately. Keypads are often combined with a control panel. Alternatives to a keypad include a security fob, fingerprint or other scanners, or deactivation through the mobile app with the right credentials.

Live Stream

Security camera systems are designed to not only save security footage for future playback, but to be viewed live. A live stream shows what is happening at the camera’s location at that moment. Traditionally, to watch a live stream the user would have to be near a monitor wired into the security system. Nowadays, most security camera systems come with a phone app that allows for remote live streaming. This technological advance really opened the doors for self-monitoring.

Local Storage

The central job of a security camera is to record video, and this footage can either be saved up in the cloud or locally. Local storage is when the saved footage is somewhere physically accessible to the user. Local storage devices include CDs, DVDs, thumb drives, external hard drives, computer or central hub built-in storage, or even videocassettes on some old analog systems.

Megapixels

A megapixel is equal to one million pixels. Pixels are what record image data that enters the image sensor of the camera. More pixels means a more detailed image. A security camera that records at 720p saves 1280 by 720 pixels per frame. When you multiply the width times height, 1280 x 720 = 921,600 pixels, or roughly 1 megapixel. Simply put, standard HD is about a 1 megapixel image, while Full HD is roughly a 2 megapixel image. A camera’s image sensor may have more pixels but only transmits the Full HD or standard HD amount. An image sensor that has more pixels and compresses down will have a clearer video.

Monitoring Center

A monitoring center is a professionally-staffed facility with the sole responsibility of responding to security alerts. Many security companies operate multiple large monitoring centers 24/7 to ensure a speedy response to alerts from their systems. There is a monthly or yearly payment to receive professional monitoring. Self-monitoring is an option with some security systems that doesn’t utilize a monitoring center and its dedicated staff.

Monitoring Service

A monitoring service offers professional monitoring of a security system for a monthly payment. The service utilizes a monitoring center and operates 24/7 in order to respond to security alerts. A monitoring service will handle the response when a user’s security system is triggered, such as investigation into the activity, sounding the alarm, and calling the authorities.

Motion Alerts

A motion alert is the security system informing the owner or monitoring center that movement has been detected by an armed motion sensor. Motion alerts from motion-detecting security cameras will be accompanied by a live stream of the event, while alerts from motion detectors will just say which device triggered the motion alert. The motion alert can be sent as a notification to the owner’s mobile app or to the monitoring center computers.

Motion Detection

In security systems, motion detection is the ability to trigger the alarm based off the movement of objects. Motion detection uses motion sensors, which work by scanning heat and detecting changes over time. Motion detection is prone to false alarms, because not all heat movement in front of a motion sensor will be criminal activity, or even human. Technology is advancing in the field to eliminate non-human motion alerts and increase the reliability of motion detection.

Motion Detector

A motion detector uses a motion sensor to look for changes in heat signatures over time. When a human or other heat-emitting object moves into motion detection range, it will trigger the device and alert the owner or monitoring center. Motion detection is prone to false alarms, because not all heat movement in front of a motion sensor will be criminal activity, or human. Motion-detecting security cameras have an advantage over simple motion detectors because the owner or monitoring center will receive the motion alert and then be able to check the live stream to see if it is a serious situation and not a false alarm.

Motion Events

A motion event is anytime a motion detector or motion-detecting security camera senses movement that triggers an alert. Traditionally, motion detectors would trigger anytime a heat source moved across the motion sensor’s field of view. Nowadays, many motion-detecting security cameras come with technology that first analyzes the motion and footage to make sure it is caused by a human. If it is, the security system will send out a motion alert and save the moment as a motion event in the system’s history. If not, no alert will go out and no motion event will be logged.

Motion Sensor

A motion sensor is a piece of hardware designed to scan heat signatures and detect changes in heat over time. Motion sensors often do so by passively absorbing the infrared rays that make up heat and checking whether the infrared moves across the sensor. This is called PIR motion sensing. If the infrared rays move, it means a heated object, such as a human, car, or animal, is in front of the sensor, and the motion sensor is triggered. More powerful motion sensors can make out movement from further away, ranging from 15ft to over 50ft. Some advanced security cameras are equipped with technology that analyzes the image to see if the detected motion is actually caused by a human. This greatly reduces the number of false alarms.

Motion Zones

A motion zone says what area within a motion sensor field of view it should be detecting movement in. The user can often define multiple motion zones. Movement in areas outside any motion zone will be ignored by the motion detector or motion-detecting security camera. For example, creating a motion zone that leaves out a sidewalk and street will greatly reduce false alarms, because all motion there will be ignored. Some security systems allow the user to adjust the motion sensitivity of each zone individually, meaning that some zones will require larger moving objects to be triggered. Often, a motion zone with low sensitivity is made for indoor cameras that covers just the floor, so that pets do not constantly trigger the alarm.

Mount

Security cameras are attached to a wall or roof with a mount. The mount secures the camera in place to prevent easy theft, but also allows for the camera’s position to be changed once it’s set. Some mounts have far better adjustability than others. Indoor security cameras may have mounts that simply let the camera be placed on top of a flat surface.

Network Video Recorder (NVR)

Often abbreviated to NVR. NVRs made for security systems receive processed video information from security cameras and allow the user to save the footage locally or watch live through a connected monitor, or with some newer models, the NVR’s phone app. Modern NVRs can perform motion detection analytics for the security cameras, and can alert the user when it detects something suspicious. NVRs are used with IP cameras, such as wireless cameras or PoE cameras. A DVR is used for BNC-wired IP cameras or analog cameras.

Night Vision

Many security cameras are equipped with night vision, which allows the camera to record footage at night or when there’s little to no light in the room. Security cameras with night vision use IR LEDs to illuminate the scene in invisible light that the camera can capture and use to brighten the image. Security cameras are often equipped with an IR cutoff filter to switch from night vision to normal mode when the sun rises or the scene gets bright enough.

NVR

See Network Video Recorder.

Optical Zoom

Only some security cameras, such as box cameras, use varifocal lenses like those found on higher-end photography or video cameras. These security cameras can remotely zoom in and out on the scene by adjusting the distances of the glass within the lens. Optical zoom is better than digital zoom in that there is no degradation of resolution when zooming in. The downsides are expensive lenses and the decreased amount that will be in focus on screen.

Outdoor Security Camera

An outdoor security camera is any security camera that is designed for use outside the home. These cameras are constructed to operate in a far greater temperature range, although the range for many outdoor cameras may not be enough to handle the extreme temperatures of some areas. Battery-powered cameras, in particular, have trouble maintaining battery charge in sub-zero temperatures. Outdoor cameras are also designed with a hard shell casing to protect the camera from rain, snow, and other environmental hazards. Check the camera’s IP rating to see how it will fair in harsh weather.

Person Detection

Some advanced motion-detecting security cameras use technology to check if the motion they picked up on is coming from a human. If it is not a human, some cameras will still alert the owner or monitoring center so that they can watch a live stream of what is happening. This can possibly be changed in the security system’s mobile app settings. If it is a human, the alert will say that a person has been detected. Person detection does not mean that the security camera can discern who specifically it is, or whether they’re a criminal or not.

PIR Motion Sensor

This stands for Passive Infrared motion sensor. Many home security cameras are designed to conserve power and wait in a low-energy standby state until they start recording. The PIR motion sensor is the part that stays on, and activates the rest of the system when it detects motion. It does so by scanning heat signatures and checking for movement of heat over time.

PIR Range 

This is the distance to which the PIR motion sensor is capable of detecting heat signatures. The range is usually greater for wired security cameras, because they don’t need to worry as much about energy usage. Distance isn’t everything, on the other hand, some security cameras allow the user to adjust the PIR range, because there may be a street or other irregular moving heat source within the default PIR range.

PoE Camera

This stands for Power over Ethernet camera. These security cameras not only transmit video over an ethernet cable to its end destination, they receive power through the same cable. This removes the need to have separate wires for powering the camera and sending information.

Professional Installation

Traditional wired security cameras have a very complex installation, and require an electrician to professionally install the system. These installations are expensive and may be somewhat destructive to the property. Nowadays, many security cameras are wireless, so don’t require an electrician. These cameras are often marketed as Do-It-Yourself security systems. However, wireless doesn’t mean battery-powered, and the option to hire professionals to install the power cable and expertly position the cameras is made available by most security companies.

Professional Monitoring

Many security camera systems are monitored by professionals in a remote destination called a monitoring center. Their job is to respond quickly and accurately to security alerts, often for 24/7. This includes assessing the situation, sounding the alarm, calling and guiding the authorities. This offers a higher degree of safety and convenience over the alternative of self-monitoring, where the owner is responsible for responding to security alerts. Many security systems do not offer the option to solely self-monitor, and require a monthly payment to fund their professional monitoring staff.

Push Notifications

This term is often used to describe the notification the owner of the security system receives when an alert reaches their mobile app. The security system pushes a notification either when a breach has occurred or when there is an important update about the health of the security system - such as low camera battery life, a WiFi disconnect, or extreme temperature effects on a camera.

Rechargeable Battery

Most battery-powered security cameras use uniquely-designed rechargeable batteries, meaning that when the battery has died, they can be recharged in the security system’s provided charging station. Rechargeable batteries have improved dramatically in recent years, and many can go for months in security cameras before needing a recharge.

Remote Storage

Remote storage is often marketed as cloud storage. For some security camera systems, recorded security footage is sent over the internet and stored on far away servers. Security companies often require a monthly subscription in order to view the saved footage, and have varying payment tiers to unlock other features associated with viewing, sharing, and saving the footage. The opposite of remote storage is local storage, and many companies that provide cloud storage don’t allow a means to locally store the footage for free.

Removable Battery

Many battery-powered security cameras are designed in such a way to let the battery be taken out and replaced. This is a convenient feature, as otherwise the security camera would have to be taken down from its position and plugged into an outlet, requiring readjustment afterwards and forcing a lack of coverage while the batteries recharge. With removable batteries, a spare battery can be put into the camera while the drained battery recharges.

SD Card

This stands for Secure Digital card. It’s a form of local storage that security camera footage can be saved to. Some security cameras are equipped with an SD card slot right in the camera, while other security camera systems will have an SD card slot in the central hub or DVR / NVR. However, there are many security systems that do not have a slot for an SD card at all and operate off of another form of storage, such as cloud storage or built-in memory.

Security Camera

A security camera is a video camera designed for long-term continuous operation. The goal of a security camera is to prevent crime and identify criminals who break-in by capturing their image, and nowadays often their audio. Security cameras vary tremendously in technology. They can be wireless and battery-powered and connect to an NVR or central hub. They can be wired and analog and connect to a DVR. Some have motion detection abilities and only record when there’s movement. Many nowadays come with a mobile app to remotely live stream the coverage.

Security System

This is the broad term used to describe all the devices used to protect a home against a home invasion. Security systems can consist of many different devices performing different functions. Important functions include motion detection, siren and lights, a keypad or other means to disarm the system, door and window sensors, security cameras, and a central hub to connect and control all these varying devices. Some products are marketed as all-in-one devices because they perform all these functions without the hassle of purchasing and setting up a system of separate pieces.

Self-Installation

This is when the customer chooses to install the security system themselves, without a professional installation. A growing number of security camera systems are DIY, meaning that they’re very easy to install. Such systems are wireless and may be battery-powered. Wired security camera systems require a professional installation because of high-skill electrical configuration requirements.

Self-Monitoring

This is when the customer is in charge of monitoring their own security system. Self-monitoring has been made more much feasible with the advent of user-friendly mobile apps that let the owner watch a live stream and view saved footage from anywhere at anytime. When the security system senses suspicious activity, it will send an alert to the owner when they’re on a self-monitoring system. The owner can then call the authorities, or ignore the alert if it’s a false alarm. Self-monitoring is not an option with many security systems. These systems require a subscription to a professional monitoring service, whose sole responsibility is to quickly and accurately respond to security alerts.

Sensors

In security systems, sensors are hardware components that perform very specific and essential security tasks. Motion sensors detect movement and trigger motion alerts. Door sensors trigger when the door they’re attached to opens. Window sensors trigger when their window opens. Audio sensors detect suspicious sounds and trigger audio alerts. Once the sensor is triggered, the security system alerts the owner or monitoring center of the suspicious activity.

Shutter Speed

See Frame Rate.

Siren

A siren generates a very loud noise to scare off criminals and alert occupants and neighbors that a crime is in progress. Sirens are measured in decibels, and are at least 100dB in order to wake up occupants and neighbors. Sirens can sometimes be found on security cameras, on the central hub, or on dedicated siren fixtures. If the system is self-monitored, sirens can sometimes be activated by the owner. If the system is professionally-monitored, they will activate the siren after reaching out to the owner. Depending on the system, sirens can be deactivated by anyone with access to the right code on the keypad, the right mobile app credentials, the correct security fob, or by answering the call from the monitoring center.

Smart Home

This term is used to describe a house with many network-connected appliances.They can either work individually off their own mobile app or connect to a central hub, where the user can use a control panel, mobile app, or voice-activated personal assistant like Alexa to control the settings on the devices. The devices are referred to as smart devices, some examples being: a smart thermostat, a smart light switch, or even a smart refrigerator.

Smart Home Automation

Smart home describes a house with many network-connected appliances that can be controlled remotely. Smart home automation describes the processes that are being done remotely. For example, a smart home has a smart thermostat. Setting the house to 70 degrees from the car is now possible because of smart home automation.

Sound Alerts

See Audio Alerts.

Sound Detection

See Audio Detection.

Sound Sensor

See Audio Sensor.

Standard HD

This stands for standard High Definition, and is a term used to describe the resolution of a video. The greater the resolution, the more detail in the image, although there are many other factors affecting video quality. Standard HD is 1280 pixels wide by 720 pixels tall, and about half the resolution of Full HD, which is 1920 pixels wide by 1080 pixels tall. Standard HD is often simply abbreviated to HD. DVDs play in HD, while Blu-Rays play in Full HD.

Surveillance Camera

See Security Camera.

Traditional Security

This term is generally used to describe a security system that is professionally monitored and given on a contract basis. Most security companies only installed there systems after a contract stipulating monthly payments for a certain number of years was signed. These systems were also professionally monitored. Recent technological developments have led to a more diverse range of systems, some of which have no contracts, can be self-installed, and allow or only work with self-monitoring.

Triggers

A security device is said to be triggered when its sensor has met certain conditions, such as detecting a change in heat sources for a motion detector. The trigger for a door sensor is when it can’t detect its paired component piece, which happens when the door opens and separates the two pieces. When such an event occurs, the programming of the device tells it to alert the owner or monitoring center that a suspicious activity is in progress.

Two-Way Audio

See 2-Way Audio.

Varifocal Lens

A varifocal lens is a camera lens that can optically zoom between two magnifications. This makes them more expensive then fixed lenses, which don’t allow for optical zooming or adjusting focus. Most security cameras are equipped with fixed lenses.

Viewing Angle

See Field of View.

Weather Resistant

A security device is said to be weather resistant when it can be used outside in the rain. However, the term weather resistant has no hard definition, and can’t be held against a company if their product doesn’t work in certain types of weather. To really know whether a device will work under certain conditions, check for its IP rating, which is a standardized, lab-tested quality check. If they don’t provide an IP rating, the device shouldn’t be used outdoors.

Weatherproof

A security device is said to be weatherproof when it can be used outside in the rain. However, the term weatherproof has no hard definition, and can’t be held against a company if their product doesn’t work in certain types of weather. To really know whether a device will work under certain conditions, check for its IP rating, which is a standardized, lab-tested quality check. If they don’t provide an IP rating, the device shouldn’t be used outdoors.

WiFi

WiFi is a wireless form of network communication. Many modern day security devices use WiFi to connect with a central hub or to the router, so that they can wirelessly transfer important security information. Information includes security footage being sent to the cloud, an NVR, or the central hub for local storage and for live streaming to your phone. Using WiFi often greatly simplifies the installation process, because no complex wiring has to happen, other than plugging the devices into an outlet if they are not battery-powered.

Window Sensors

A window sensor is a security device that gets placed on the edge of a window. It is designed in two pieces, when they are pulled apart, the device sends a signal to the central hub that is has been triggered. The hub then alerts the user or monitoring center that a breach has occurred. Window sensors can be purchased by themselves, but will not work without a central hub. Not all window sensors work with all hubs so double check compatibility. Be sure to arm the window sensor or it will not trigger. Without security cameras pointed at the scene, the owner and monitoring center won’t know for sure if it’s a false alarm.

Wire-free

This is a term used to describe security cameras and other devices that have no cables or wires whatsoever. This means that the device uses WiFi or some other wireless technology, and is also battery-powered. When a device only needs a power cable, because it sends its data over WiFi or via some other wireless technology, the device is called a wireless device. When a security device needs a power cable and a wire to send information across, it is described as a wired security device.

Wired

This is a term used to describe security cameras and other devices that need a power cable and a wire for data-transfer. These cables may be combined into one using an ethernet cable, and devices that work this way are called PoE devices. When a device only needs a power cable, because it sends its data over WiFi or via some other wireless technology, the device is called a wireless device. Devices that don’t need any cables at all, because they use batteries and use WiFi or some other wireless technology, are called wire-free devices.

Wireless

This is a term used to describe security cameras and other devices that send data over WiFi or via some other wireless technology, such as Z-Wave, Zigbee, or Bluetooth. Wireless devices can still use a cable to plug into an outlet, so are not wire-free like battery-powered wireless devices. Devices that need both a power cable and a cable for data-transfer are called wired devices.

Z-Wave

This is a wireless network protocol. It operates similarly to WiFi, but is used mainly for communication between devices in the smart home automation market. Smart products and security devices that can use Z-Wave will say so. Such devices will easily pair with and communicate with a Z-Wave compatible central hub. Use of Z-Wave has grown tremendously as the smart home market has boomed, and using the Z-Wave protocol has allowed for different companies to let their smart devices work together. Another commonly-used wireless protocol between smart home devices is Zigbee.

Zigbee

This is a wireless network protocol. It operates similarly to WiFi, but is used mainly for communication between devices in the smart home automation market. Smart products and security devices that can use Zigbee will say so. Such devices will easily pair with and communicate with a zigbee compatible central hub. Using the Zigbee protocol has allowed for different companies to let their smart devices work together. Another commonly-used wireless protocol between smart home devices is Z-Wave.

Zoom

See Digital Zoom and Optical Zoom.