Infrared light is a type of electromagnetic radiation that has a longer wavelength than visible light, but shorter than microwaves. It is not visible to the human eye, but can be detected by special sensors or cameras. Infrared light is commonly used in various applications such as thermal imaging, communication, spectroscopy, and remote sensing. It is also used in medical imaging, agriculture, security systems, and industrial processes. Infrared light has the ability to penetrate through certain materials and can be used to detect objects or changes in temperature. It is an important research area that continues to advance and find new applications in various fields.