Security Camera & Surveillance Glossary

Analog High Definition — a video transmission format for analog security cameras that supports resolutions up to 8MP (4K) over standard coaxial cable. AHD is one of four major HD analog standards (alongside HD-TVI, HD-CVI, and CVBS). AHD cameras require a compatible DVR — they will not work with IP-based NVR systems.

On-camera or cloud-based artificial intelligence that classifies motion events beyond simple pixel change. Modern AI detection distinguishes between people, vehicles, animals, and packages — reducing false alerts caused by shadows, trees, and weather. Higher-end cameras (Arlo, Hikvision ColorVu) include AI detection on-device; budget cameras rely on cloud AI processing which requires a subscription.

The opening in a camera’s lens that controls how much light reaches the image sensor, expressed as an f-number (e.g., f/1.6, f/2.0). Lower f-numbers = wider aperture = more light — critical for low-light and night vision performance. A camera with f/1.6 aperture will capture significantly brighter night footage than one with f/2.8 at identical settings.

The proportional relationship between a camera’s video width and height. Most security cameras record in 16:9 widescreen (standard HD format). Some doorbell cameras record in 1:1 (square) or 9:16 (tall portrait) format — Ring’s “Head-to-Toe” view uses a taller ratio to capture both a visitor’s face and packages on the ground simultaneously.

A motorized lens mechanism that automatically adjusts the aperture opening in response to changing light conditions — similar to how the human eye’s pupil dilates and contracts. Cameras with auto iris maintain consistent exposure across scenes with dramatic lighting changes, such as a driveway that transitions from bright sunlight to deep shade. Common in professional-grade IP cameras.

The amount of video data processed per second, measured in megabits per second (Mbps) or kilobits per second (Kbps). Higher bitrate = better video quality but more storage used. A 4K camera at 8Mbps produces noticeably better footage than the same camera at 2Mbps, but uses 4x the storage space. Most NVR systems allow per-camera bitrate adjustment.

A cylindrical, directional camera housing shaped like a bullet or tube. Bullet cameras are visible deterrents — their obvious design signals that surveillance is in place. They excel at long-range monitoring of a specific direction (driveways, parking lots, approach paths) but have a narrower field of view than dome cameras. Most include an integrated IR illuminator in the housing.

A camera setting that improves the visibility of subjects in front of bright light sources (windows, car headlights, outdoor sunlight). Without BLC, a person standing in front of a bright window appears as a dark silhouette while the window is correctly exposed. BLC adjusts the exposure specifically around the darker subject, sacrificing some background detail to make the subject visible.

In security camera context, bandwidth refers to two things: (1) network bandwidth — the data capacity of your internet or local network, which affects how many cameras can stream simultaneously; and (2) NVR incoming bandwidth — the maximum total bitrate the NVR can receive from all connected cameras. Exceeding NVR bandwidth causes dropped frames even with open recording channels.

Closed-Circuit Television — the original term for security camera systems where video signals are transmitted to a specific, limited set of monitors rather than broadcast publicly. The term originated in analog surveillance systems but is now used colloquially to refer to all security camera systems, including modern IP-based systems. In the US, “security cameras” and “CCTV” are used interchangeably in consumer contexts.

The ability to capture color video in low-light or near-darkness without switching to black-and-white IR mode. Achieved through one of two technologies: (1) Starlight sensors — ultra-sensitive image sensors that amplify available ambient light; (2) White-light illuminators — visible LED floodlights that activate on motion. Color night vision is superior for incident identification because it captures clothing colors, vehicle colors, and skin tone.

The method used to reduce video file size for storage and transmission. H.264 is the older, widely compatible standard. H.265 (HEVC) achieves the same quality as H.264 at roughly half the file size — critical for reducing storage costs on high-resolution cameras. H.265+ is a proprietary enhancement (used by Hikvision and Dahua) that further reduces file size by dynamically adjusting compression based on scene activity.

A security camera deliberately designed or placed to be concealed from view. Covert cameras are legal in most US states for property owners monitoring their own property without audio recording. However, placing hidden cameras in areas where people have a reasonable expectation of privacy (bathrooms, bedrooms, changing areas) is illegal regardless of property ownership. Always consult an attorney before installing hidden cameras.

Composite Video Baseband Signal — the original analog video standard used in traditional CCTV systems, limited to standard definition (480i/576i). CVBS cameras produce noticeably lower quality footage than HD standards and are not recommended for new installations. Most modern DVRs still include CVBS inputs for backward compatibility with legacy camera systems.

Video footage stored on remote servers operated by the camera manufacturer or a third-party provider, accessible via internet. Advantages: footage is protected even if the camera is stolen or damaged, accessible from anywhere, automatic backup. Disadvantages: requires ongoing subscription fees, dependent on internet connectivity, privacy concerns about manufacturer data access. Ring, Nest, and Arlo all use cloud storage as their primary recording method.

A proprietary HD analog video transmission standard developed by Dahua Technology, supporting resolutions up to 4K over standard coaxial cable. HD-CVI cameras are primarily used in Dahua DVR systems. While Hikvision uses HD-TVI and Dahua uses HD-CVI as their native formats, modern DVRs from both brands support all major HD analog formats in compatibility mode.

A security camera enclosed in a dome-shaped housing, typically mounted flush to a ceiling or wall. Dome cameras offer a wide field of view and are more discreet than bullet cameras — the dome housing makes it difficult to determine which direction the camera is pointing, which itself acts as a deterrent. Vandal-resistant dome cameras (IK10 rating) are reinforced against physical attack and are popular for commercial installations.

Dynamic Domain Name System — a service that automatically updates a domain name to point to your current IP address when your internet provider changes it. Most US residential internet connections use a dynamic IP address that changes periodically. DDNS allows remote access to your NVR or IP cameras using a consistent domain name (e.g., myhome.ddns.net) rather than a constantly changing IP address. Hikvision (Hik-Connect), Dahua (DMSS), and many others offer free DDNS services.

Digital Video Recorder — a device that receives video from analog (coaxial cable) security cameras, converts it to digital format, and stores it on an internal hard drive. DVRs process and encode video centrally, unlike NVRs where IP cameras do their own encoding. DVRs are recommended primarily for upgrading existing analog coaxial cable infrastructure. For new installations, NVR systems are generally preferred.

A software-based technique that improves visibility in scenes with extreme contrast between bright and dark areas — like a camera pointed at a bright window from a dark interior. DWDR processes the image digitally to recover detail in both bright and dark regions. It is less effective than true WDR (which uses hardware-based dual-exposure capture) but is found in most budget-to-mid-range cameras as a cost-effective alternative.

A security camera or alarm system that the homeowner installs and monitors themselves, without professional installation or monitoring services. The majority of US residential security camera sales are DIY systems. DIY systems range from a single wireless camera (Ring, Blink) to complete 8-camera NVR setups. Professional monitoring (paying a company to watch your cameras) is optional and available as an add-on for most major brands.

Standardized network cable used to connect IP security cameras to PoE switches or NVR systems. For security camera installations: Cat5e supports PoE up to 100 meters (328 ft) and is sufficient for most home installations. Cat6 is recommended for runs over 50 meters or where future 4K+ cameras are planned. Cat6a is required for PoE++ (high-power PTZ cameras with heaters).

Video storage on a device physically located at the camera itself — typically a microSD card inserted directly into the camera. Edge storage eliminates dependency on an NVR or cloud service, making it a useful backup when the main recording system is unavailable. Most consumer wireless cameras (Wyze, Reolink, Eufy) support microSD edge storage as their primary or secondary recording method.

A digital method of controlling exposure time by reading the image sensor in sequence, rather than using a physical mechanical shutter. Security cameras universally use electronic shutters. Shutter speed affects motion blur — a fast shutter (1/1000s) freezes motion clearly, while a slow shutter (1/30s) introduces blur but allows more light in low-light conditions. Auto-shutter mode adjusts this balance automatically.

The angular extent of the observable world captured by a camera, measured in degrees. Most security cameras have a horizontal FOV between 90° and 130°. Wider FOV (110–130°) captures more area but subjects appear smaller. Narrower FOV (60–90°) captures less area but subjects appear larger and more identifiable. PTZ cameras have variable FOV controlled remotely. Note: manufacturers sometimes overstate FOV by including the diagonal measurement rather than horizontal.

The embedded software that controls a security camera’s or NVR’s core functions. Firmware updates are released by manufacturers to fix bugs, patch security vulnerabilities, add new features, and improve performance. Always update firmware regularly — outdated firmware is one of the most common causes of IP camera security vulnerabilities. Most modern cameras support automatic OTA (over-the-air) firmware updates via their companion app.

A security camera integrated with a motion-activated LED floodlight, typically providing 2,000–5,000 lumens of illumination. The light serves dual purposes: enabling full-color night vision footage and actively deterring intruders by illuminating them. Floodlight cameras require hardwired power installation and are not available as battery-only models. Popular brands: Ring Floodlight Cam, Arlo Pro 3 Floodlight, Eufy Floodlight Cam.

The number of individual images (frames) captured per second of video. Standard security camera frame rates: 15fps (acceptable for most surveillance), 25/30fps (smooth, standard for most modern cameras), 60fps (smooth slow-motion capable, rare in security cameras). Higher frame rates use proportionally more storage. For license plate capture, 30fps is recommended to avoid motion blur on moving vehicles.

A location-based feature that automatically adjusts your security camera’s behavior based on your smartphone’s GPS location. When your phone leaves a defined geographic area (your “geofence”), cameras arm and enable alerts. When you return home, cameras disarm or switch to “home” mode. Available on Ring, Arlo, and Nest systems. Reduces false alerts from your own activity when you’re home.

A camera mounted on a motorized, stabilized platform that can track moving subjects automatically. Some consumer security cameras (Eufy SoloCam Tracking, Reolink TrackMix) use gimbal or optical tracking to follow a person or vehicle as it moves through the frame. Distinct from PTZ cameras — gimbal cameras track automatically, while PTZ cameras are controlled manually by an operator.

The most widely adopted video compression standard, used in the majority of security cameras sold before 2020. H.264 offers good video quality with broad hardware and software compatibility. It has been largely superseded by H.265 for new security camera systems, but remains relevant because virtually all devices (phones, computers, NVRs, TVs) can play H.264 video without issues.

The successor to H.264, offering equivalent video quality at approximately 50% of the file size. H.265 is the current standard for modern security camera NVR systems and is strongly recommended for 4K cameras where storage efficiency is critical. Most cameras and NVRs manufactured after 2018 support H.265. Note: H.265 requires more processing power to decode — older or budget playback devices may struggle.

A technique that captures multiple exposures simultaneously and combines them to reveal detail in both bright and dark areas of a scene. In security cameras, HDR is particularly valuable for scenes with strong backlighting or mixed indoor/outdoor lighting. True hardware HDR (using multiple sensors or exposures) is superior to software-based WDR. Look for “True HDR” or “Hardware WDR” specifications when buying cameras for challenging lighting environments.

Apple’s smart home protocol for security cameras, offering end-to-end encrypted video processing and storage in iCloud. Unlike Ring or Arlo, HomeKit Secure Video processes video analysis (person detection, motion) on a local Apple device (HomePod, iPad, Apple TV) before uploading to iCloud — so the manufacturer never sees your footage. Requires an iCloud+ subscription. Compatible cameras: Logitech Circle View, Eufy (some models), Arlo (some models).

The primary storage device inside NVR and DVR systems. Security surveillance requires purpose-built surveillance HDDs (Western Digital Purple, Seagate SkyHawk) rated for 24/7 continuous write operations. Standard desktop or laptop HDDs are not designed for this workload and will fail prematurely in a security recorder. Surveillance HDDs are available in 1TB–20TB capacities; 4TB–8TB is recommended for most US home installations.

A digital security camera that transmits video data over an ethernet network (either wired via PoE or wirelessly via WiFi). IP cameras perform their own video encoding on-device before sending the compressed stream to an NVR or cloud service. IP cameras are the standard for all modern security camera systems and have replaced analog CCTV cameras in most new US installations. They support remote access, PTZ control, audio, and AI features that analog cameras cannot.

An international standard (IEC 60529) measuring a device’s resistance to solid particles and liquids. Expressed as “IP” followed by two digits: the first indicates dust protection (0–6), the second indicates water protection (0–9). For outdoor security cameras: IP65 (dust-tight, protected against water jets) is the minimum acceptable rating. IP66–IP67 provides stronger protection for harsh US weather conditions.

Infrared light is electromagnetic radiation just beyond the visible spectrum — invisible to the human eye but detectable by camera sensors. Security cameras use IR LEDs to illuminate a scene in complete darkness, producing black-and-white night vision footage. IR range is measured in feet/meters and represents the maximum distance at which the camera’s IR illuminators can provide usable night vision. Effective real-world IR range is typically 60–70% of the manufacturer’s stated range.

A rating that measures a camera’s resistance to mechanical impact, expressed as IK followed by a number from 00–10. IK10 is the highest rating, indicating the camera can withstand a 20-joule impact (equivalent to a 5kg object dropped from 40cm). IK10-rated vandal-proof dome cameras are recommended for commercial installations, schools, and any location where physical camera tampering is a concern.

The dedicated chip inside a security camera that processes raw sensor data into a final video image. The ISP applies noise reduction, color correction, white balance, WDR processing, and compression. The quality of the ISP often determines image quality more than the raw megapixel count of the sensor. Hikvision, Dahua, and Sony are major ISP manufacturers whose chips appear across cameras of varying brand names.

A video resolution of approximately 3840×2160 pixels (8 megapixels), offering 4x the detail of 1080p Full HD. In security cameras, 4K provides the detail needed for license plate capture at distances over 30 ft and facial recognition at distances exceeding 30 ft. Trade-offs include significantly higher storage requirements and the need for a 4K-compatible NVR. In practice, for most US home uses, 2K (4MP) offers sufficient detail at substantially lower storage cost.

The delay between what happens in front of a camera and what appears on a monitor or phone screen. Low-latency live view (under 500ms) is important for two-way audio conversations (video doorbells) and active monitoring. High-latency (2–5 seconds) is acceptable for recorded playback but creates awkward interaction on doorbell cameras. Cloud-based cameras typically have higher latency than local NVR systems due to data round-trip to remote servers.

License Plate Recognition (LPR) or Automatic Number Plate Recognition (ANPR) — technology that automatically reads and records vehicle license plates in camera footage. Effective LPR requires specific camera placement (nearly level with the license plate), minimum 2K resolution, adequate lighting, and software processing. Hikvision and Dahua offer dedicated LPR cameras for commercial use. Consumer cameras can capture plate numbers in good conditions but rarely offer automatic recognition.

Video footage stored on a device physically located at the property — either in an NVR/DVR with a hard drive, or on a microSD card inside the camera itself. Local storage has no monthly subscription cost, works without internet, and keeps footage under your physical control. The trade-off is that footage is at risk if the device is stolen or damaged. Many users combine local storage (primary) with cloud backup (secondary).

One million pixels. Security camera resolution is often expressed in megapixels: 2MP = 1080p Full HD, 4MP = 2K, 8MP = 4K Ultra HD, 12MP = 4K+ used in some professional cameras. Higher megapixel counts allow greater digital zoom and cropping while maintaining detail. Note that megapixel count is only one factor in overall image quality — lens quality, sensor size, ISP processing, and lighting all significantly affect real-world results.

The ability to detect movement and trigger recording, alerts, or actions. Three main types: (1) Pixel-based — detects changes in pixel values (most common, can trigger false alerts from shadows, lighting changes); (2) PIR (Passive Infrared) — detects heat signatures of warm bodies, reducing false alerts from non-living motion; (3) AI/Smart detection — classifies motion events as person, vehicle, animal, or package, dramatically reducing false alerts. Most modern cameras combine pixel-based detection with AI classification.

A user-defined area within the camera’s field of view that triggers motion alerts. Areas outside the motion zone are ignored even if motion occurs there. Properly configured motion zones are the single most effective way to reduce false alerts — excluding the road, neighbor’s driveway, swaying trees, and other non-relevant motion sources. Most consumer cameras (Ring, Arlo, Wyze) offer simple zone selection; professional cameras support pixel-level zone masking.

A removable flash memory card used for on-camera edge storage in wireless and standalone IP cameras. Security cameras require high-endurance microSD cards (rated for continuous write cycles) rather than standard camera/phone cards. Popular options: SanDisk High Endurance, Western Digital Purple microSD. Use class ratings of at least U3/V30 for 4K cameras. Capacities of 64GB–256GB are typical for home security cameras.

Network Video Recorder — a device that receives pre-encoded video streams from IP cameras over a network connection and stores them to an internal hard drive. Unlike DVRs, NVRs do not encode video themselves — this is done by each camera independently. NVRs connect to cameras via PoE ethernet ports or wirelessly. Most modern NVRs include a built-in PoE switch, eliminating the need for a separate network switch. Recommended for all new US security camera installations in 2026.

The ability to capture usable video footage in low-light or complete darkness. Achieved through infrared (IR) LEDs that illuminate the scene invisibly, a highly sensitive image sensor (starlight), white-light LEDs (color night vision), or a combination. Night vision range varies significantly — advertised ranges are typically achieved under ideal conditions; real-world effective range is 60–70% of the stated figure. Always verify night vision claims against independent tests before purchasing.

The National Defense Authorization Act (NDAA) Section 889 prohibits US federal government agencies and their contractors from purchasing or using security cameras from Hikvision, Dahua, Huawei, ZTE, and Hytera. This ban applies only to federal government use — it does not restrict private individuals or businesses from purchasing these brands. “NDAA compliant” cameras are those not manufactured by the banned entities and are required for any federal government or military installation.

An open industry standard that enables interoperability between IP security cameras and recording devices from different manufacturers. An ONVIF-compatible Hikvision camera can stream video to a Dahua NVR, and vice versa. However, ONVIF compatibility provides only basic interoperability (video streaming) — advanced features like smart motion detection, PTZ presets, and audio are typically only fully functional within the same brand’s ecosystem.

Text or graphics overlaid on camera footage, typically showing camera name, date, time, and temperature. OSD allows easy identification of which camera corresponds to which footage when reviewing recordings across a multi-camera NVR system. Most NVRs allow custom OSD text, font size, and position. POS (Point of Sale) integration is an advanced OSD feature used in retail businesses to overlay transaction data on camera footage.

Passive Infrared sensor — detects the heat (infrared radiation) emitted by warm objects (humans, animals) moving through the sensor’s field. PIR sensors reduce false alerts from non-heat-emitting motion sources like shadows, light changes, and blowing trees. Many battery-powered cameras (Blink, Ring Stick Up) use PIR as their primary trigger to conserve battery — the camera only activates and begins recording when PIR detects a warm body, rather than continuously.

A technology standard that delivers both electrical power and data through a single ethernet cable, eliminating the need for separate power adapters at each camera location. PoE cameras only require one cable run per camera — both power and video travel through the same Cat5e/Cat6 cable to the NVR. Standard PoE (IEEE 802.3af) provides up to 15.4W per port, sufficient for most IP cameras. PoE+ (802.3at) provides up to 30W for PTZ cameras and cameras with heaters.

A camera with motorized pan (horizontal rotation), tilt (vertical rotation), and optical zoom capabilities controlled remotely via software or a joystick controller. PTZ cameras can monitor a wide area with a single unit, following moving subjects or zooming into specific areas of interest. They are significantly more expensive than fixed cameras and require more bandwidth. Common in commercial and parking lot applications; increasingly available for home use.

An AI feature that identifies and alerts when a package (box, parcel) is detected in the camera’s view — typically at a front door or porch. Package detection distinguishes between a person visiting (person detection) and a package being delivered or removed. Available on Ring, Arlo, Nest, and Wyze with appropriate subscription plans. Particularly popular in US suburbs where porch piracy (package theft) is a common concern.

A router configuration that directs incoming internet traffic on a specific port to a device on your local network — enabling remote access to an NVR from outside your home. Port forwarding requires a static IP address or DDNS service, and opens a potential security vulnerability if not configured with strong passwords and a non-standard port number. Most modern NVR manufacturers offer P2P cloud relay as a more secure alternative that doesn’t require port forwarding.

The number of pixels in a video frame, determining the level of detail captured. Common security camera resolutions: 1080p (2MP) = 1920×1080, 2K (4MP) = 2560×1440, 4K (8MP) = 3840×2160. Higher resolution allows greater digital zoom and cropping in post-incident review. Resolution affects storage requirements linearly — 4K footage requires approximately 4× the storage of 1080p footage at the same frame rate and compression settings.

A network protocol used to stream live video from an IP camera to a recording device or viewer. RTSP is the backbone of most professional IP camera streaming — NVRs use RTSP to pull video streams from cameras. RTSP access also allows cameras to stream to third-party NVR software (Blue Iris, iSpy, Shinobi) and home automation platforms (Home Assistant). Consumer cameras (Ring, Arlo, Nest) typically disable RTSP access to prevent use outside their proprietary ecosystems.

The ability to view live camera feeds, review recorded footage, and manage camera settings from a smartphone, tablet, or computer outside the home network. Remote access for consumer cameras (Ring, Arlo, Wyze) is managed entirely through the manufacturer’s cloud service. For NVR systems, remote access is achieved via P2P cloud relay (easier, slightly higher latency) or port forwarding with DDNS (more control, requires configuration).

A camera image sensor with extremely high light sensitivity that produces color footage in near-darkness (0.001–0.01 lux) without switching to black-and-white IR mode. Starlight sensors are used in cameras marketed as having “color night vision” without a white-light LED. They produce better low-light color quality than standard sensors but require some minimal ambient light — total darkness will still trigger a switch to IR mode. Sony Starvis and Starvis 2 sensors are the most widely used starlight sensors in security cameras.

An umbrella term for AI-powered video analysis features that go beyond basic motion detection — including person detection, vehicle detection, animal detection, package detection, face recognition, line crossing detection, and perimeter intrusion detection. Smart detection dramatically reduces false alerts and enables targeted notifications (“person detected at front door” vs. generic “motion detected”). Available on premium consumer cameras and standard on professional Hikvision/Dahua cameras.

The physical dimensions of the camera’s image sensor, typically expressed as a fraction of an inch (1/2″, 1/2.8″, 1/3″). Larger sensors capture more light and produce better low-light performance than smaller sensors at the same megapixel count. A 2MP camera with a 1/2″ sensor will outperform a 4K camera with a 1/3″ sensor in dark conditions. Sensor size is rarely prominently advertised by consumer camera brands but significantly impacts real-world night performance.

A central hub device used by some wireless camera systems (Arlo, Eufy) that connects cameras via a proprietary radio frequency (rather than standard WiFi) and bridges them to your home network. SmartHubs extend camera range beyond typical WiFi limits, reduce battery drain compared to direct WiFi cameras, and enable local storage of footage. Arlo’s SmartHub is required for local video storage without a cloud subscription.

A recurring monthly or annual fee paid to a camera manufacturer for cloud storage of recorded footage and/or access to advanced AI features. Common US subscription plans: Ring Protect ($10–20/month), Arlo Secure ($12.99/month per camera or $17.99 for unlimited), Nest Aware ($8–15/month), Wyze Cam Plus ($1.99/month per camera). Subscriptions significantly affect the total cost of ownership — always calculate the 3-year cost including subscriptions when comparing cameras.

A camera feature that triggers an alert when the camera is physically moved, covered, spray-painted, or repositioned. Tamper detection alerts notify the owner that someone is attempting to defeat the surveillance system, often indicating that an intrusion attempt may be imminent or ongoing. Available as standard on most commercial IP cameras; less common on consumer cameras. Some systems also alert when camera coverage changes unexpectedly due to cable tampering.

A camera feature that includes both a microphone (to hear what’s near the camera) and a speaker (to speak to people near the camera) — enabling real-time voice communication through the camera. Two-way audio is a standard feature on video doorbells and is increasingly common on outdoor security cameras. Quality varies significantly: premium cameras offer echo cancellation and noise suppression for clear conversation; budget models produce muffled, delayed audio.

A proprietary HD analog video transmission standard developed by Hikvision, supporting resolutions up to 8MP (4K) over standard coaxial cable. HD-TVI is the native format of Hikvision DVR systems. While Hikvision and Dahua each developed their own native formats (TVI and CVI respectively), modern DVRs from both brands support all major HD analog standards (TVI, CVI, AHD, CVBS) in multi-format mode.

A networking protocol that allows devices on a local network to automatically configure port forwarding rules on a router without user intervention. While UPnP makes remote camera access easier to set up, it is a significant security risk — it can be exploited by malware to open unauthorized ports on your network. Cybersecurity best practice: disable UPnP on your router and configure port forwarding manually if needed, or use the camera manufacturer’s P2P service instead.

The consumer label for 4K resolution (3840×2160 pixels) — exactly 4 times the pixel count of 1080p Full HD. In security cameras, Ultra HD provides the detail necessary for reliable license plate capture, facial recognition at longer distances, and wide-area monitoring where digital zoom into specific areas is regularly needed. Ultra HD recording requires a compatible NVR, adequate storage (4× that of 1080p at equal quality), and Cat6 cabling for PoE cameras.

A camera housing rated to withstand deliberate physical attack — typically IK10 rated (20-joule impact resistance). Vandal-proof cameras use polycarbonate or metal domes and housings designed to prevent damage from hammers, rocks, and other impact tools. Required for commercial installations, schools, parking structures, and any outdoor location where camera tampering is a realistic threat. Most residential cameras are not IK-rated — IK10 is predominantly found in commercial dome cameras.

A logical network segment that isolates devices from each other even when on the same physical network. For security cameras, placing cameras on a dedicated IoT VLAN prevents a compromised camera from accessing other devices on your main network (computers, phones, smart home devices). A best practice for Hikvision, Dahua, and other Chinese-manufactured IP cameras in cybersecurity-conscious installations. Requires a managed router/switch to configure.

A camera lens with adjustable focal length, allowing the field of view to be changed after installation. Manual varifocal lenses require physical adjustment (using a screwdriver). Motorized varifocal (or “motorized zoom”) lenses adjust remotely via the camera’s software — crucial for cameras mounted at height where physical access is difficult. Varifocal lenses allow installers to fine-tune coverage area after mounting, making placement more flexible than fixed-focal cameras.

A hardware technique that simultaneously captures multiple exposures of the same scene and combines them to reveal detail in both bright highlights and dark shadows. True hardware WDR is essential for cameras facing strong backlight (a door with a bright window behind it, a parking lot entrance with headlights). WDR strength is measured in decibels (dB) — 120dB WDR handles more extreme lighting contrast than 80dB WDR. Budget cameras often advertise “digital WDR” (DWDR) which is a software approximation.

An IP security camera that connects to a home network wirelessly via 802.11 WiFi rather than a physical ethernet cable. WiFi cameras are battery-powered or plug-in powered, with no ethernet cable required. Trade-offs versus wired cameras: susceptible to WiFi interference and dead zones, dependent on WiFi signal quality, battery-powered models require periodic charging. The convenience of wireless placement makes WiFi cameras the most popular choice for US residential buyers.

A security camera that receives power and transmits video data through a physical cable — either ethernet (PoE IP cameras) or coaxial cable (analog cameras). Wired cameras offer consistent, uninterrupted recording without battery concerns, and are not affected by WiFi range or congestion. The trade-off is a more complex installation requiring cable routing through walls, ceilings, or conduit. Recommended for permanent installations where maximum reliability is required.

A hardware or software mechanism that automatically reboots a camera or NVR if it becomes unresponsive or crashes. Watchdog timers prevent the common scenario where a camera freezes and stops recording without the owner knowing — the camera self-reboots and resumes normal operation. Available as a software setting on most professional NVRs and as a hardware feature in industrial-grade cameras. For consumer cameras, a smart plug with scheduled reboots achieves a similar result.