Modem (DSL)

(In DSL) A device that converts IP data into a format suitable for transmission over PSTN phone lines. These were necessary for DSL home Internet connections. Today modems, along with DSL itself, are not especially common due to more advanced technologies (cable and fiber internet) and the societal pivot away from landline to mobile phones.

(In Cable Internet) A device that translates IP traffic into a format suitable for transmission over CATV networks, similar to DSL modems.