DSL, or Digital Line Subscriber Internet is when companies, traditionally the old telephone companies use their old copper lines to provide internet connections to their subscribers. First, most Internet connections came into people's houses through dial up. That is when the computer would dial a number and connect to another computer and through that computer they would connect to the world wide web. The trouble was that when you were using dial up connection you couldn't also use your telephone because the computer was using the phone line.
Then, the phone companies figured out how to be able to use the phone at the same time as being connected to the Internet. They just use a different frequency that the phone call. Usually thay have to have a filter to separate the signals. This is called DSL or digital line subscribers. It was a better, faster connection than dial up. The legacy telephone companies like AT&T, EarthLink, CenturyLink and Frontier offer DSL Internet.
About the same time, cable companies figured out that they could also use their cable lines coming into people's homes to connect them to the Internet. Cable Internet connection was much faster than dial up too. The cable companies like Charter, Comcast, Mediacom and Cox all offer high speed cable Internet.
Both cable companies and telephone companies have been upgrading to fiber optic lines to improve the speed of Internet connections and high speed fiber optic Internet is avaiable in many areas.
