Infrared Radiation (IR) is a type of ElectroMagnetic Radiation (EMR) with a wavelength that is longer than visible light. Infrared waves are used in a variety of applications, including night vision, thermal imaging, and remote control.
Night vision devices use infrared technology to see in the dark by detecting the heat signature of objects. Thermal imagers also use infrared waves to detect heat signatures and create images based on temperature differences. Remote controls work by sending out infrared signals that are picked up by a receiver on the device being controlled.
The human eye can only detect visible light, but we can feel infrared radiation as heat. This makes it useful for many applications such as heating homes and cooking food. Infrared waves are also used in medical imaging and treatment, as well as astronomical research.