Identification
The act of recognizing one person as being unique from all other people.

Identification Card
A card that stores the information necessary to verify the identity of the cardholder.

Infrared Light
Light with a wavelength that is too low to be seen by the human eye.

Infrared Motion Sensor
A sensing unit that detects motion based on the disruption of infrared light waves.

Input
An electronic sensor on a controller that detects a change of state in a device outside the controller. See Normally-Closed, Normally-Open.

Insertion Card
A card that must be inserted into a reader for the reader to retrieve the information stored on the card.

Intelligent Device
Any type of microprocessor-based input, output, or sensor device that has free-standing logic capability. These devices can be programmed with instructions that allow them to make their own decisions regarding granting access and sounding alarms. They also can communicate with a host computer to receive new instructions or to send event message logs.