ADSL is a method of multiplexing a broadband internet connection over an existing landline telephone wire that is still being used for voice band telephone.Wireless (usually Wi-Fi) is a method of connecting computers to a router via radio signals in the microwave band. It is usually used to support a Local Area Network (the range of the radio signal is limited) but the router may be connected to the internet via an ADSL modem, a SDSL modem, a cable modem, a satellite modem, etc. if desired.