A very high speed Internet connection in which the bandwidth can be divided and shared by multiple simultaneous signals
Asymmetric Digital Subscriber Line - this is used to enable faster data over a copper telephone line than a conventional voice band modem.
Analogue and Digital signal
Speech or music can be transmitted as a analouge or digital signal
digital signals carry more information for second then analouge . This is the same whether optical fibres, cable or radio waves
digital signals maintain their quality over long distance better than analouge.