It depends what you are asking. If you mean you are planning on buying a DSL service from a ISP and want to connect it to your computer that is pretty much your standard DSL internet connection and you would use a modem or router. Routers are much more commonly used. The installation guy from the phone company likely would help you get everything hooked up
If you are asking if you can use the phone wires in your house to say connect to a router that has a ethernet port in another part of the house. Technically there are devices that do that function but they are rather expensive. They are not simple to find and are sold as ethernet extenders but their main purpose is to say connect a location that is over the 300ft ethernet...