Far-infrared refers to a specific range of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves, typically between 15 micrometers and 1 millimeter. This type of radiation is often associated with heat, as it is emitted by warm objects, including the human body. In various applications, far-infrared is used in technologies like infrared saunas and heating pads, which are believed to provide therapeutic benefits by promoting relaxation and improving circulation. Additionally, it plays a role in astronomy for studying celestial bodies, as it can penetrate dust clouds that obscure visible light.