JPEG: A digital image format commonly used in digital recording, for storing high-quality color and grayscale photographs in compressed bitmap form.

Lag: The image retention of an object after the object has been scanned. Sometimes, it causes a smearing effect.

LAN: Local Area Network; multiple computers connected together to share information. Shared information could be e-mail, files, and printers.

Line Lock: In an AC-powered camera, it synchronizes the field sync pulses, to the frequency of the voltage input (line voltage).

Lux: A unit of measuring the intensity of light. (1 FC = 10 Lux). A common measurement of a CCTV camera’s ability to view in low-light conditions.

Manual iris lens: A lens with a manual adjustment to set the iris opening (F stop). Generally used for indoor or fixed lighting applications.

Matrix Switcher: A switching device that routes camera inputs to any monitor outputs for viewing

Monochrome: Having only one color. In CCTV and television it is black and white.

Motion Detection: A feature that uses the video signal from a camera to determine movement (pixel changes) and react by recording the video or setting an alarm condition

MPEG: MPEG is a video compression method commonly used in digital recording. MPEG-1 is a standard for CD-ROM video and audio. MPEG-2 is a standard for full-screen, broadcast quality video.MPEG-4 is a standard for video telephony.

Network: Computers connected together to share information. Think of a network as a city and the computers as houses within the city. Two types of networks are LAN and WAN.

NTSC: NTSC (National Television System Committee) is an organization that formulated the standards for the current United States color television system. This system is used in most countries of the Americas, as well as other parts of the world. NTSC employs 525 lines per frame, 29.97 frames per second and 59.94 fields per second.

PAL: PAL (Phase Alternation Line) is a European color TV system featuring 625 lines per frame, 25 frames per second and 50 fields per second. PAL is used mainly in Europe, China, Malaysia, Australia, New Zealand, the Middle East, and parts of Africa.

Pixel: Short for picture element, Pixels are the tiny dots of information that make up a digital image. The more pixels there are on the camera's image sensor (CCD or CMOS), the higher the image resolution will be. The higher the resolution, the clearer an enlarged print can be.

Power: The rate at which electrical energy is applied to or taken from a device. Power is expressed in terms of watts.

Raster: The rectangular pattern of scanning lines upon which the picture is produced. The illuminated portion of the video monitor.

RS232: A commonly used computer serial interface.

Server: A computer and its software that provides some service for other computers connected to it through a network.

Signal to noise ratio: The ratio between the video signal and unwanted electrical noise.

Simplex (multiplexer): A multiplexer that allows the user to look at multi-screen images or perform time multiplex recording.

Spot Monitor: A feature on DVRs that allows a secondary monitor (s) to monitor certain video channels.

S/N (Signal to noise) Ratio: Measure of noise levels of a video signal: the higher the number the better.

Sync: Electronic pulses that are inserted in the video signal for the purpose of maintaining the picture information in the correct position.

T.V.L. (Television Lines - Resolution): The maximum number of changes between light and dark on a picture across 3/4 of the width dictates the resolution of a CCTV product, measured in TVL. Broadcast video is 540 TVL. CCTV high resolution is currently considered 480 TVL and above.

Zoom lens: A lens system that may be effectively used as a wide angle, standard or telephoto lens by varying the focal length of the lens.