Infrared is easily generated and doesn't suffer electromagnetic interference, so it is nicely used to communication and control. Some other light emissions could contain infrared as well, and that can interfere in this communication. The sun is an example, since it emits a wide spectrum or radiation.
Infrared Photography is another aspect of infrared. infrared (IR) light pass through to the camera, while all or most of the visible light spectrum are being blocked.
INFRARED in Summary