Copper is broadband via the telephone cable
DSL is a broad term used for the Internet that you can get through the copper network. Some also call it broadband via the telephone jack.
Nostalgia with possibilities
Today Internet via the copper network is improved over the years and TDC NET can deliver over 300 Mbit /s download speeds in some places. With DSL, however, a certain speed is not guaranteed, because the distance from your home to the nearest point of interconnect can cause noise and thus lower speed options.