Definition: The term broadband refers to any type of transmission technique that carries several data channels over a common wire. DSL service, for example, combines separate voice and data channels over a single telephone line. In DSL, voice fills the low end of the frequency spectrum and data fills the high end.
In home networking, “broadband” usually refers to high-speed Internet access using this transmission technique. Both DSL and cable modem are common broadband Internet technologies. So-called broadband routers and broadband modems are network devices that support both DSL and cable.