DSL (Digital Subscriber Line) provides you with an internet signal over the telephone lines which run to your home.
Traditional telephone service and Dial-up internet only use a very small portion of the available frequency ranges which could pass over a telephone wire.
DSL uses a portion of the remaining frequency ranges. This allows DSL to attain high speeds over the same medium (telephone wires) without competing with your phone service.
Cable internet provides you with an internet signal over the coaxial cable lines which run to your home.
Cable internet makes use of unused channels (predefined frequency ranges) to pass your data instead of television programming.
So what's the difference?
In the end, internet is internet. Both DSL and Cable provide high speed access and are generally equivalent under good conditions. There are a few key differences though.
- DSL requires an active phone line. This means that you either need active POTS service with a telephone provider, or you will need to pay an additional monthly fee to run a Dry Loop (a phone line used ONLY for DSL) to your home.
- DSL is a dedicated line. Your line is yours and only yours. The speed you get is the speed you will always get.
- The quality of a DSL line depends on your distance from the CO/Remote that you are connected to. As your signal flies down the telephone line to get to the CO/Remote, it meets constant resistance and interference which causes the signal to become worse and worse the further it needs to travel. If your home is too far away from this point, you may end up with lower speeds than you expected or you simply may not qualify for service.
- Cable is a shared connection. The line that runs to your home is a branch of a larger trunk which also feeds your neighbor's homes. This means that if that trunk is not wide enough to feed your neighborhood it may become congested causing decreased speeds.
- Cable uses coaxial cables which are very heavily shielded. This means that unlike DSL, distance is of very little concern to a cable connection. If you qualify for service, you should be able to get any of our offered speeds.
Well, what one should I get?
A good way to start is by knowing your current service.
Do you have DSL Internet, but don't qualify for the speed you desire? Is your Cable Internet congested all the time causing it to run unbearably slow? Or do you love your current service and wish to take advantage of the cost savings of not having to swap modem technologies?
Asking these questions gives you a good idea as to what you need. If you currently experience a problem, sometimes changing your service type is a good way to fix it - depending where the problem is of course! But this is a good place to start to figure out what you need, why you need it, and how to go about it.