ADSL broadband is a connection provided over home telephone lines. The UK has a landline infrastructure so when you have an ADSL connection you need to rent your phone line from a provider. If you already have an existing phone line, it is added onto the package. It uses an existing phone line to provide internet access, while still allowing the phone line to be used for phone calls/faxes. It does this by transmitting data at very high frequencies, compared to how a regular modem works. By splitting your existing telephone line signal into two, one for voice and the other for data.