The camera with this feature will automatically detects available light and instantly adjust the brightness and gain under low light condition by switching to Infra-Red(IR) black and white mode.

Decibel widely used to measure the loudness of sound. The decibel is more generally a measure of the ratio between two quantities,and can be used to express a variety of measurements in acoustics and electronics.

Direct Current is the type of electricity. All of the electric charges move in one direction.

One type of AutoIRIS, will automatically adjust the amount of light allowed to enter. It requires simply a DC input from the camera without signal converted.

Dynamic Domain Name Service is a service that maps Internet domain names to IP addresses. It works with dynamic IP addresses.

A decoder is a device that is undoing the encoding so that the original information can be retrieved. Just as the reverse of an encoder.

A process that converts interlaced signals into progressive signals. The interlaced video must first be de-interlaced to produce progressive video for viewing in a progressive video system.

Domain Host Configuration Protocol: is a protocol for automatically assigning dynamic IP addresses to individual devices on a network.

A device can automatically be given an IP address each time it connects to a network with DHCP server.DHCP server also assigns the subnet mask, Default Gateway, and Domain Name Server IP address.

See Digital Input.

A Digital Input will detect a voltage or no voltage condition, and generates a logical 0 or 1, high or low. It could be used to trigger an alarm or other events.

To trigger an output alarm, the digital output will short both pins and complete the external device's circuit. The normal state is open.

Digital Zoom takes part of the image and expends it. The resulting image appears bigger but not as sharp as with an optical zoom.

Domain Name System translates Internet domain and host name into corresponding IP addresses. It only works with static IP addresses.

See Digital Output.

To centralize the management of the Windows computers by using Domains. The domain server is the server that takes control of the users' accessing on the network.

See Full-duplex.

D-sub is used to indicate the type of connector for the VGA interface.