Acronym for "Asymetric Digital Subscriber Line". It's a technology which allows high speed transmission of digital data through the usual telephone lines. The transmission is asymetrical as its speed is faster towards the client than from client to server. This is justified by the fact most of the traffic is going from server to client (like when you are consulting Web pages) and a small part is going the opposite way (when you are sending information).

          You are the subscriber to the Internet connection. The lines are the plain old telephone lines.

          As ADSL is using higher than vocal frequencies it's possible to use the phone while surfing.

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