Angle of View - The scene angle that a video camera lens can show on the monitor, like Diagonal Angle, Horizontal Angle and Vertical Angle, usually described in degree.
Aspect Ratio - The ratio of the vertical to the horizontal image size; 4:3 is the PAL standard.
Bandwidth - The capacity of the transmission medium stated in bits per second or as a frequency. Or, the amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second (bps) or bytes per second.
Bit - Abbreviated with small “b”. Binary Digit. The smallest unit of data in a computer.
bps - Bits Per Second is the unit used for measuring line speed, the number of information units transmitted per second.
Byte - Abbreviated with capital “B”. A unit of data that is eight bits long and is used by most computers to represent a character such as a letter, number or symbol.
Camera format (Sensor Size) - Video camera’s CCD chips format; 1/4″, 1/3″, 2/3″, 1″ etc.
Camera Sensor - Video image sensor. CCD or C-MOS chip.
CCD - Charge Coupled Device. A video image sensor chip.
CCTV (Closed Circuit Television) - Is a Television system that sends a signal to one or more monitors rather than broadcasting over a public network, hence closed-circuit. A standard CCTV system will normally include a CCTV camera (for capturing video), transmitters and receivers (to transfer the video from the source to where it is recorded), a recording system (for video playback), and a monitor (for video monitoring). CCTV systems are primarily used for security purposes inside and outside buildings.
CMOS - Complementary - Metal Oxide Semiconductor. A video image sensor chip that produces much lower quality picture than CCD chip.
DVR - Digital Video Recorder; records video pictures digitally.
Electronic Shutter - Compensates for moderate light changes in indoor applications without the use of auto iris lenses.
Field Of View (FOV) - The width, height or diameter of a scene to be monitored. Usually determined by the focal length of a lens, the sensor format and the distance to the objects.
Focal Length (FL) - The distance from the center of a lens to the focal point (sensor). The longer the focal length, the narrower is the angle of view.
Frame - A whole video image; is composed of two interlaced fields. A CCD chip produces 30 frames per second at NTSC system and 25 frames at PAL.
Gigabyte (GB) - 1024 Megabyte = 1073741824 Bytes
IP - Internet Protocol. A set of rules to send and receive messages at the Internet address level.
IP CCTV (IP Video) - Internet Protocol Closed Circuit Television
Iris - An adjustable opto-mechanical aperture built into a camera that controls the amount of lights coming through the lens.
JPEG - Joint Photographic Experts Group. A graphic image file or a image compression algorithm.
Kilobyte ( Kb) - 1024 Bytes
Kbps - Kilobits per second. A measure of bandwidth.
LAN - Local Area Network. A group of computers and associated devices that share a common communications line.
Megabyte (MB) - Megabyte = 1024 Kilobyte = 1048576 Bytes
Mbps - Megabits per second. A measure of bandwidth.
MPEG - Moving Picture Experts Group. A standard for a digital video & audio compression.
NTSC - National Television System Committee; formulates standards for American colour television system. NTSC system has 525 horizontal scan lines and 30 frames per second.
PAL - Phase Alternating Line system. A colour television system used in Europe, Australia, parts of Africa and the Middle East. It has 625 horizontal scan lines and 25 frames per second.
Pan - Rotating or scanning a camera side ways to view an area in a horizontal direction.
Pan and Tilt - A Camera mounting device that allows movement in both side ways and up or down.
Server - A computer program that provides services to other computer programs in the same or other computers. Or, the computer that a server program runs.
Switcher - A device that allows the video signals from multiple cameras to be displayed on a monitor, or recorded on a VCR one at a time in sequence.
TCP - Transmission Control Protocol. A set of rules to exchange messages with other Internet points at the information packet level.
Web Camera - A CCTV Camera with built-in web server computer.
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