broadband, term describing the radiation from a source that produces a broad, continuous spectrum of frequencies (contrasted with a laser, which produces a single frequency or very narrow range of frequencies). A typical broadband-light source that can be used for either emission or absorption spectroscopy is a metal filament heated to a high temperature, such as a tungsten lightbulb. Sunlight is also broadband radiation. In the context of Internet access, the term broadband has come to mean Internet speeds faster than those that could be achieved through dial-up. See also broadband technology.