Camera-system terminology is full of acronyms and technical terms. The glossary walks you through the most common — from basics to advanced.
Resolution and image
- Megapixel (MP)
- Number of points (pixels) on the image in millions. 2 MP = 1920×1080 (Full HD), 4 MP = 2560×1440, 8 MP = 3840×2160 (4K).
- Resolution
- Width × height in pixels. Higher resolution = more detail, but also higher bitrate and storage.
- Frame rate (FPS)
- Frames per second. 15 FPS is enough for normal recording, 25 FPS is smooth video, 50 FPS = slow motion.
- WDR (Wide Dynamic Range)
- Technology for handling scenes with large light/shadow contrast. Distinguish digital DWDR (lower quality) from True WDR (real).
- HDR
- High Dynamic Range — similar to WDR, optimises high-contrast scenes.
Compression and streaming
- H.264
- Older video codec, still the most common. Good quality/size ratio.
- H.265 (HEVC)
- Newer codec, ~50% smaller bitrate than H.264 at the same quality. Needs a more powerful processor.
- H.265+
- Proprietary improvement over H.265 with smart bitrate — saves 30–70%.
- Bitrate
- Amount of data per second (Mb/s). Higher = better quality but more disk and network load.
- Keyframe (I-frame)
- Full frame in the stream. Between them are P-frames (delta). Interval 1–5 s.
- VBR / CBR
- Variable / Constant Bit Rate. VBR is smarter (less data when scene is quiet), CBR is steady.
Network and protocols
- RTSP
- Real-Time Streaming Protocol — protocol for live video. URL format:
rtsp://user:password@IP:554/stream - RTMP
- Real-Time Messaging Protocol — originally Flash, today for streams to YouTube/Twitch.
- HLS
- HTTP Live Streaming — Apple's protocol for browser and mobile streams.
- ONVIF
- Open Network Video Interface Forum — standard for camera–recorder communication. Profile S (video), Profile T (AI).
- P2P (Peer to Peer)
- Protocol for connecting devices without a public IP. Handles NAT and port forwarding via the manufacturer's cloud.
- DDNS
- Dynamic DNS — assigns a fixed name to a dynamic IP (camera.mydomain.com). Alternative to P2P.
- Port forwarding
- Forwarding a port from public IP to LAN. Allows external camera access but is risky.
PoE and power
- PoE (Power over Ethernet)
- Power over UTP cable simultaneously with data. Eliminates a separate power cable.
- IEEE 802.3af
- Standard PoE up to 15.4 W per port. Enough for most IP cameras.
- IEEE 802.3at (PoE+)
- Extended PoE up to 30 W. Required for cameras with heaters, motorzoom or PTZ.
- IEEE 802.3bt (PoE++)
- High power up to 90 W per port. For specific applications.
Cameras and hardware
- Bullet
- Compact cylindrical camera, typically outdoor. Easy to mount.
- Dome
- Dome camera. Vandal-resistant, hides viewing direction.
- PTZ (Pan-Tilt-Zoom)
- Camera with motorised movement (pan, tilt, zoom). Suited to large areas.
- Fisheye
- Panoramic camera with extremely wide view (180–360°).
- Motorzoom
- Optical zoom driven by a motor — focus and zoom remotely.
- IP67 / IP66
- Protection rating against water and dust. IP66 = strong rain, IP67 = brief immersion.
- IK10
- Impact resistance. IK10 = up to 20 J (a hammer strike).
Night vision
- IR (infrared)
- Light invisible to the human eye. A camera with IR LEDs captures black-and-white image in the dark.
- Smart Light / Warm Light
- White LED floodlight for colour night vision. Activates on motion.
- Color24 / Full Color / Starlight
- Extremely sensitive sensor for colour image at minimal light (street lamp, moon).
- Sony STARVIS
- Sony's series of sensitive sensors. Best night vision in low light.
AI features
- Motion Detection
- Detection of motion in the image. Basic feature, often raises false alarms (leaves, flies).
- Smart Detection / AI Detection
- Detection of specific objects (person, vehicle). Fewer false alarms.
- Face Recognition
- Recognising specific faces from a database. Watch out for GDPR!
- Line Crossing
- Virtual line — camera alarms on crossing.
- Area Intrusion
- Virtual zone — alarm on entry/exit.
- ROI (Region of Interest)
- Area of interest. Camera increases bitrate in the important part of the image and saves around it.
Storage
- NVR
- Network Video Recorder — recorder for IP cameras.
- XVR
- Hybrid recorder for AHD + IP cameras.
- DVR
- Digital Video Recorder — older, for analogue cameras.
- Surveillance HDD
- Specialised hard drive for 24/7 recording. WD Purple, Seagate SkyHawk lines.
- RAID
- Redundant Array of Disks — data backup / striping across multiple disks.
Other useful terms
- Cloud ID
- Unique device identifier for P2P connection.
- CMS
- Central Management System — software for managing multiple NVRs.
- Cascade
- Connecting switches or NVRs in a chain.
If you come across a term not listed here, write to us — we keep extending the glossary.