(1) (Digital Video Recorder)DVR A device that records video from up to a dozen or more surveillance cameras onto a hard disk.
The frame rate can be switched from real time to time lapse in order to save storage space.
Digital recorders are more flexible than earlier analog VHS tape systems, and the video can be easily transmitted over a computer network.
(2) (Digital Video Recorder) Also known as a "personal video recorder" (PVR) or "hard disk recorder,"
a DVR is a consumer device that allows the viewer to pause and rewind any broadcast, cable or satellite TV program as well as record and play back selected programs (see live pause).
An order of magnitude more flexible than earlier videocassette tape recorders (VCRs), an entire season of programs from one or more favorite series can be recorded.
(1)Closed Circuit TV) A self-contained surveillance system comprising cameras, recorders and displays for monitoring activities in a store or company.
Earlier analog CCTV systems used VHS tape; either a single VCR for each camera, a "quad VCR" that recorded four low-res images or a time-lapse recorder that handled multiple cameras.
Subsequently, specialized digital video recorders (DVRs) with multiple analog inputs superseded VHS tape machines.
(2) Increasingly, digital "network cameras" are used that transmit over Ethernet or Wi-Fi and offer greater camera installation flexibility.
Analog CCTV recorders have a fixed number of camera ports, whereas Wi-Fi cameras are easily added, and Ethernet ports can be expanded at minimal cost.
See 960H and network camera.
(1) An Internet Protocol camera, or IP camera, is a type of digital video camera that receives control data and sends image data via an IP network.
They are commonly used for surveillance but unlike analog closed-circuit television (CCTV) cameras, they require no local recording device, only a local area network.
(1)Bayonet Nut Coupling) BNC A commonly used plug and socket for audio, video and networking applications that provides a tight connection.
Using a mount somewhat similar to the way a bayonet (knife) is mounted onto the end of a rifle, BNCs are used to connect a variety of different coaxial cable types.
After the plug is inserted, it is turned, causing pins in the socket to be pinched into a locking groove on the plug.
(2) BNCs differ from many connectors because of their snap-lock architecture, which keeps the plug firmly in its socket.
Network Video Recorder)NVR A computer that records video transmitted over the network from multiple digital CCTV surveillance cameras.
See network camera, CCTV and hybrid DVR
(Pan Tilt Zoom) PTZ A wall or ceiling mounted camera that is able to move its lenses horizontally (pan) and vertically (tilt),
as well as change its focal length between near and far (zoom in/zoom out). See network camera.