DSL

When you connect to the Internet, you might connect through a regular modem, through a local-area network connection in your office, through a cable modem or through a digital subscriber line (DSL) connection. DSL is a very high-speed connection that uses the same wires as a regular telephone line.

Here are some advantages of DSL:

You can leave your Internet connection open and still use the phone line for voice calls.

The speed is much higher than a regular modem (1.5 Mbps vs. 56 Kbps)

DSL doesn't necessarily require new wiring; it can use the phone line you already have.

The company that offers DSL will usually provide the modem as part of the installation.

 lets you make regular telephone calls even when you're online!

But there are disadvantages:

A DSL connection works better when you are closer to the provider's central office.

The connection is faster for receiving data than it is for sending data over the Internet.
The service is not available everywhere.