Infrared (IR) refers to a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. It is commonly used in various applications, including remote controls, thermal imaging, and night vision technology. The human eye cannot see infrared light, but it can be felt as heat. Infrared radiation is divided into three categories: near-infrared, mid-infrared, and far-infrared. Each category has different uses, such as fiber optic communication for near-infrared and heat lamps for far-infrared. Overall, infrared technology plays a significant role in both everyday devices and advanced scientific research.