Video Recording and Security Camera Glossary

Glossary of terms used across this site. Covers personal video recording, digital video recorders, network video recorders, and the full security camera stack from analog CCTV to modern 4K PoE systems.

Video Recording Core

  • PVR (Personal Video Recorder). Consumer device that records broadcast TV to an internal hard drive for time-shifted playback. TiVo popularized the term in 1999. Often used interchangeably with DVR on retail sites.
  • DVR (Digital Video Recorder). Digital recorder, originally for cable/satellite TV. In modern retail, overwhelmingly refers to analog CCTV recorders that accept BNC coax inputs.
  • NVR (Network Video Recorder). IP-based recorder that ingests Ethernet streams from PoE cameras. Produces H.264 or H.265 files at native camera resolution without re-encoding.
  • HVR (Hybrid Video Recorder). Recorder that accepts both analog (BNC) and IP (Ethernet) camera inputs on a single unit. Sometimes called a hybrid DVR.
  • VCR (Video Cassette Recorder). Analog magnetic-tape recorder dominant from the late 1970s to early 2000s. Replaced by PVRs/DVRs. JVC (VHS) and Sony (Betamax) fought the first format war.
  • CCTV (Closed Circuit Television). Surveillance video system where signals are not publicly broadcast. Modern CCTV spans legacy analog-over-coax to current IP-over-Ethernet installations.
  • Time-shifting. Recording a live broadcast for later playback. Pause live TV, rewind during a broadcast, and skip commercials all fall under this concept.
  • Continuous recording. Mode where the recorder writes to storage 24/7. Essential for evidence-grade security footage. Opposite: motion-only recording.
  • Motion-only recording. Mode where the recorder writes only when motion is detected. Cuts storage use by 60-80 percent compared to continuous.
  • Retention time. Number of days of footage the recorder keeps before overwriting oldest files. Common targets: 14, 30, 60, 90 days.
  • Video loop. Automatic overwriting of oldest recordings once storage is full. All modern DVR/NVR units default to loop mode.
  • Channel count. Number of camera inputs a DVR/NVR supports. Common sizes: 4, 8, 16, 32.

Analog Signal Formats

  • AHD (Analog High Definition). Korean high-definition analog-over-coax standard. Supports 720p, 1080p, 4MP, 5MP, and 4K over standard RG59 coax.
  • TVI (Transport Video Interface). Hikvision-developed HD analog standard. Competes with AHD. Supports up to 8MP over coax with backward compatibility to legacy CCTV cameras.
  • CVI (Composite Video Interface). Dahua’s HD analog standard. Supports 1080p and above. Most modern hybrid DVRs auto-detect AHD, TVI, and CVI on each BNC input.
  • CVBS (Composite Video Baseband Signal). Legacy analog standard from the VCR era. PAL or NTSC. Maximum effective resolution is 720×576 (PAL) or 720×480 (NTSC).
  • BNC (Bayonet Neill-Concelman). Bayonet-locking coaxial connector used for CCTV video signals. Recognizable by its quarter-turn twist-lock collar.
  • RG59. Thin 75-ohm coaxial cable used for analog CCTV video. Maximum effective run is about 750 feet for 1080p AHD.
  • RG6. Thicker 75-ohm coax with lower signal loss. Used for longer runs, satellite TV, and 4K analog CCTV up to 1200 feet.
  • Siamese cable. Combined BNC video plus power cable sold in a single bonded sheath. Simplifies camera wiring on analog installations.
  • Balun (Balanced-Unbalanced). Signal converter that transmits BNC video over Cat5e/Cat6 twisted pair. Extends analog range to 1,000 feet without quality loss.
  • HDMI (High-Definition Multimedia Interface). Digital video output connector on every modern DVR and NVR. Carries up to 4K 60fps with audio on a single cable.

Networking and Cabling

  • PoE (Power over Ethernet). IEEE 802.3af standard that delivers up to 15.4W of DC power alongside data over a single Cat5e/Cat6 cable. Standard for modern IP cameras.
  • PoE+ (802.3at). Extended PoE delivering up to 30W. Required for PTZ cameras, floodlight cameras, and units with integrated IR illuminators.
  • PoE++ (802.3bt). Delivers up to 60W (Type 3) or 100W (Type 4). Supports heating elements, powerful floodlights, and large multi-sensor cameras.
  • Cat5e. Twisted-pair Ethernet cable supporting 1 Gbps up to 100m. Minimum spec for PoE IP cameras at 1080p resolution.
  • Cat6. Upgraded twisted-pair supporting 10 Gbps at shorter runs and 1 Gbps at 100m. Standard for new 4K PoE camera installations.
  • RJ45. 8-pin connector used on Ethernet cables. Crimped to Cat5e/Cat6 cable ends for termination.
  • ONVIF (Open Network Video Interface Forum). Vendor-neutral standard for IP camera and NVR interoperability. Profile S covers basic streaming, Profile T adds H.265 and advanced metadata, Profile M adds AI event analytics.
  • RTSP (Real Time Streaming Protocol). Standard stream-over-network protocol for IP cameras. NVR software tunes to rtsp:// URLs to pull camera feeds.
  • DDNS (Dynamic DNS). Service that maps changing public IP addresses to a stable hostname. Enables remote access to home DVR/NVR without a fixed public IP.
  • VPN (Virtual Private Network). Encrypted tunnel from phone/laptop to home network. Safer than DDNS port forwarding for remote camera access.
  • P2P (Peer-to-Peer). Vendor service that proxies the connection between camera/recorder and phone app. Simplifies remote access but routes video through vendor servers.

Digital Video Codecs

  • MPEG-2. Video compression standard used in DVDs and original ATSC 1.0 broadcasts. Larger file sizes than modern codecs.
  • H.264 (AVC, Advanced Video Coding). Dominant video codec from 2005 to 2020. Supported by every phone, browser, and media player. Baseline for most mid-priced IP cameras still on market.
  • H.265 (HEVC, High Efficiency Video Coding). Successor to H.264. Same visual quality at roughly 50 percent smaller file size. Standard for new 4K IP cameras and NVRs.
  • H.266 (VVC, Versatile Video Coding). Next-generation codec from 2020. Another 30-50 percent size reduction vs H.265. Adoption slow due to patent complexity.
  • AV1. Royalty-free video codec developed by AOMedia. Used by YouTube, Netflix, and some consumer NVRs. Strong competitor to H.266.
  • DivX. Late-1990s consumer MPEG-4 variant. Used for compressing TV recordings in the early TiVo-hacker era.
  • WMV (Windows Media Video). Microsoft codec family from 2003-2010. Used in Windows Media Center. Now superseded by H.264/H.265.
  • Bitrate. Amount of data per second a video uses, in Mbps. Higher bitrate equals better quality and larger file size.
  • CBR (Constant Bitrate). Video encoding where bitrate stays fixed regardless of scene complexity. Predictable storage use.
  • VBR (Variable Bitrate). Encoding that adjusts bitrate to scene complexity. Quieter scenes use less data, busy scenes more. Better quality per storage byte.
  • GOP (Group of Pictures). Interval between keyframes in a video stream. A shorter GOP means faster seeking but larger files. Typical 1-3 second GOP for security footage.
  • Keyframe (I-frame). Full reference frame that does not depend on adjacent frames. Security systems use keyframe-aligned playback for frame-accurate evidence retrieval.

Storage and Retention

  • HDD (Hard Disk Drive). Spinning magnetic storage. Surveillance-specific drives (WD Purple, Seagate SkyHawk) are rated for 24/7 write cycles and high vibration tolerance.
  • SSD (Solid State Drive). Flash memory storage. Faster and silent but more expensive per GB. Sometimes used for NVR OS; HDD still preferred for bulk video storage.
  • NAS (Network Attached Storage). Networked storage device. Synology and QNAP units run NVR software (Surveillance Station) for camera recording at scale.
  • microSD. Flash memory card. Edge storage on individual cameras (32GB to 512GB). Acts as backup when network/NVR fails.
  • RAID 0. Disk striping without redundancy. Double the speed, double the failure risk. Not used for surveillance.
  • RAID 1. Disk mirroring. Two drives hold identical data. Survives a single drive failure. Standard for small NVR installations.
  • RAID 5. Striping with distributed parity across 3+ drives. Survives a single drive failure. Most common RAID in mid-size surveillance.
  • RAID 6. Striping with double parity. Survives two simultaneous drive failures. Standard for 8+ drive enterprise NVR arrays.
  • Hot spare. Idle drive inside the NVR that auto-rebuilds the array when a working drive fails. Cuts rebuild window to minutes.
  • Storage pool. Logical grouping of RAID arrays presented as one volume. Cameras write to storage pool; pool distributes to underlying drives.

Camera Types and Form Factors

  • Bullet camera. Cylindrical fixed-direction camera mounted on walls or eaves. Longest focal length options; best for licence-plate and long-range identification.
  • Dome camera. Hemispherical ceiling-mounted housing hides camera direction from viewer. Harder to tell which way the lens is pointing. Standard for retail and indoor surveillance.
  • Turret camera. Eyeball-style camera that can swivel in its housing. Combines dome discretion with bullet-like flexibility. Popular for residential eaves.
  • PTZ camera (Pan-Tilt-Zoom). Motorized camera that can rotate 360 degrees and zoom optically. Covers a wide area but only records one direction at a time.
  • Fisheye camera. Ultra-wide 360-degree camera with a fisheye lens. Useful for ceiling-mounted omnidirectional coverage of a single room.
  • Doorbell camera. Compact camera integrated into a doorbell. Ring, Nest Doorbell, Eufy Doorbell Dual dominate the consumer segment. Adds motion detection plus two-way audio.
  • Floodlight camera. Hardwired outdoor camera with integrated high-lumen LED floodlight. Ring Floodlight Cam Pro popularized the form factor for active deterrence.
  • Box camera. Traditional rectangular CCTV body. Accepts interchangeable lenses. Older commercial form factor; less common today.
  • Wireless camera. Camera that connects to the network over Wi-Fi. Battery or wall-plug powered. Easy install but depends on Wi-Fi range and battery discipline.
  • Wired camera. Camera that connects to the network over Ethernet (PoE) or to a DVR over coax (BNC). Most reliable connection; requires cable runs.

Image Technology

  • CMOS (Complementary Metal-Oxide-Semiconductor). Dominant image sensor technology. Lower cost, lower power, built-in image processing. Every consumer camera in 2026 uses CMOS.
  • CCD (Charge-Coupled Device). Legacy image sensor with better low-light and less noise than early CMOS. Mostly replaced by modern Sony STARVIS CMOS sensors.
  • STARVIS. Sony CMOS sensor line optimized for low-light security applications. Used in most premium PoE cameras for superior night-vision detail.
  • Resolution. Camera pixel count expressed as width x height. Common: 1MP (720p), 2MP (1080p), 4MP, 5MP, 8MP (4K), 12MP.
  • Frame rate (fps). Frames captured per second. 15 fps for motion-triggered recording, 30 fps for smooth live-view, 60 fps for sports or fast action.
  • IR night vision. Near-infrared illumination invisible to the human eye. Produces black-and-white nighttime video up to 100+ feet of range.
  • Color night vision. Full-color low-light recording using larger sensors plus white-light LED assist. Reolink Argus 4 Pro and Hikvision ColorVu are leading implementations.
  • True WDR (Wide Dynamic Range). Hardware-level HDR that handles scenes with high-contrast (backlit entryways, bright sunlight behind a doorway) without blown highlights.
  • IP65 / IP66 / IP67. Ingress Protection ratings. IP65 resists dust and low-pressure water jets, IP66 handles high-pressure water jets, IP67 survives 1m submersion for 30 minutes.
  • IK10. Impact resistance rating. Survives 20-joule impact without functional failure. Standard for vandal-resistant dome cameras.
  • Field of view (FOV). Angle of coverage expressed in degrees. Wider FOV (100-110 degrees) for close-range coverage, narrower (50-70 degrees) for long-distance.
  • Focal length (mm). Lens specification. 2.8mm is wide, 4mm is medium, 6mm and above zoom in on details. Varifocal lenses adjust focal length at install time.

Motion Detection and AI Analytics

  • PIR (Passive Infrared) sensor. Hardware heat-signature detector that triggers recording only when a warm body moves into view. Dramatically reduces false alerts vs pure pixel motion.
  • Pixel delta motion. Software-based motion detection that fires when enough pixels change between frames. Older method, prone to false positives from wind and lighting shifts.
  • Smart motion detection. AI-classified motion that distinguishes person, vehicle, animal, and package. Baseline feature on all 2026 flagship cameras.
  • Motion zones. User-configured rectangles within the frame that enable motion detection. Everywhere else is ignored. Prevents alerts from a busy sidewalk or passing street traffic.
  • Exclusion mask. Inverse of motion zones: user-defined areas the camera ignores for motion events. Useful for masking a neighbor’s window or a tree branch.
  • Person detection. Specific AI class that fires only on human-shaped moving objects. Standard on Ring Protect Pro, Nest Aware, Arlo Secure, Reolink AI.
  • Vehicle detection. AI classifier for cars, trucks, motorcycles. Useful for driveway cameras.
  • Package detection. AI class for delivery boxes left near the door. Ring, Arlo, and Nest support this class.

OTA Broadcasting and Cord-Cutting

  • OTA (Over-the-Air). Broadcast TV received via an antenna. Free, unencrypted, and delivered in ATSC 1.0 or ATSC 3.0.
  • ATSC 1.0. US digital TV standard since 1996. Carries up to 1080i video and 5.1 audio in an MPEG-2 stream.
  • ATSC 3.0 (NextGen TV). New US standard supporting 4K HDR video, HEVC compression, and IP-based delivery. Deployed in most major US markets since 2021.
  • Tuner. Hardware that decodes the broadcast signal. OTA DVRs with 4 tuners can record four channels simultaneously.
  • Tablo. Consumer OTA DVR brand. 4th Gen 4-Tuner (2024) is the current subscription-free default.
  • HDHomeRun. Silicondust network tuner that serves OTA streams to multiple devices over LAN. Paired with Channels DVR software for recording.
  • Channels DVR. Commercial DVR software for OTA (via HDHomeRun) or cable content. Runs on NAS, Mac mini, or Raspberry Pi.
  • EPG (Electronic Program Guide). Data feed that populates channel schedules on a DVR. Pulled from Gracenote, Zap2it, or vendor-specific services.
  • Cord-cutting. Practice of dropping cable/satellite TV in favor of OTA, streaming services, or both. Accelerated after 2015 with Netflix dominance.
  • Streaming bundle. Multi-service subscription (Disney+/Hulu/ESPN, YouTube TV, Sling TV) replacing cable DVR functionality with cloud DVR.
  • Broadcast Flag. FCC mandate from 2003 that would have required digital TV tuners to honor copy-protection bits. Struck down by a US appeals court in 2005 but shaped years of DVR design.
  • DMCA (Digital Millennium Copyright Act). 1998 US law making it illegal to circumvent DRM. Relevant to DVR hackers transferring recordings off TiVos or defeating CableCARD copy protection.
  • CableCARD. FCC-mandated card issued by cable operators. Decodes encrypted cable channels inside retail DVRs (TiVo Series 3, Moxi, Ceton). Phased out after 2020.
  • CCI (Copy Control Information). Flags on CableCARD streams that mark a program as “copy once,” “copy never,” or “copy freely.” Enforced by consumer DVRs.
  • HDMI HDCP. Digital rights management on HDMI outputs. Prevents screen capture and bit-for-bit copying of protected content.
  • NDAA 889 (Section 889). US federal law banning Hikvision and Dahua cameras from federal government installations. Relevant to integrators specifying cameras for government contracts.
  • GDPR. EU regulation with implications for cloud-storage security cameras. Requires data locality and user consent for facial recognition features.
  • UL / ETL certification. Safety compliance marks required for indoor electrical products sold in North America. Cheap no-name cameras often skip these.

Historical and Legacy Terms

  • HMO (Home Media Option). 2003 TiVo feature that added networked music, photos, and remote scheduling to Series 2 DVRs. First real step toward connected DVRs.
  • TiVo Series 1. Original TiVo DVR (1999). 14-hour hard drive, dial-up modem for guide data, IR-blaster control of cable boxes. Hacker-modifiable.
  • TiVo Series 2. 2003 DVR with USB ports. Enabled third-party Ethernet adapters, the Home Media Option, and mass wired networking. Defined modern DVR usage.
  • TiVo Series 3. 2006 DVR with native HD recording and CableCARD support. First consumer unit to record HD cable.
  • TiVo Roamio / Bolt / Edge. 2013 / 2015 / 2019 standalone retail DVRs. Edge for Antenna is the current OTA model still manufactured.
  • WeaKnees. Retailer and how-to source for TiVo upgrades. Invented the Twinbreeze cooling kit for dual-drive Series 2 upgrades. Active since 2003.
  • Hinsdale. Named after the Chicago suburb where author Steve Cook lived. Hinsdale published the definitive TiVo hard-drive upgrade how-to in 2001-2002.
  • ReplayTV. Competitor to TiVo from 1999-2007. Added automatic commercial skip, which triggered Hollywood lawsuits. Bankrupt in 2005 and killed off by 2011.
  • MythTV. Open-source Linux DVR since 2002. Still active. Direct ancestor of modern Linux-based NVR projects like MotionEye and Frigate.
  • SnapStream Personal Video Station. Windows DVR software from 2002-2010. Evolved into Beyond TV, eventually discontinued.
  • Beyond TV. SnapStream’s later-generation Windows DVR software. Popular in the mid-2000s alongside Windows Media Center.
  • Windows Media Center. Microsoft’s DVR software included with Windows XP MCE, Vista Premium, Windows 7, and Windows 8 Professional. Discontinued in Windows 10 (2015).

Smart Home Integration

  • Alexa. Amazon voice assistant. Controls compatible cameras via “Alexa, show me the front door” commands routed to Echo Show or Fire TV displays.
  • Google Home. Google voice assistant and hub. Integrates with Google Nest cameras natively; supports third-party cameras via Works with Google Assistant.
  • Apple HomeKit. Apple smart home framework. Supports HomeKit Secure Video (iCloud recording) on compatible cameras. Strong privacy guarantees.
  • Matter. Cross-vendor smart home standard (Apple, Google, Amazon, Samsung). Promising for cameras but slow to roll out as of 2026.
  • IFTTT (If This Then That). Automation service connecting cameras to third-party devices. Trigger Philips Hue lights when motion detected, for example.
  • Webhook. HTTP callback from a camera to a custom URL. Used for self-hosted automations (Home Assistant, Node-RED).
  • Home Assistant. Open-source home automation platform. Strongest third-party integration layer for heterogeneous camera setups.
  • Frigate NVR. Open-source NVR with integrated AI object detection. Runs on a home server; widely used in Home Assistant setups.