which telecommunications service allows internet and telephone service to work over the same phone line

DSL telecommunications service allows internet and telephone service to work over the same phone line

Explanation:

DSL means Digital Subscriber Line

This provides "high speed internet connection" through "telephone line". The beauty of it is that it does not require any "special wires" in additional. Only the "modem" will be additional part of expenses and a separate installation. But this would be provided by the "Service provider" itself.

In the classical method of using internet via phone will allow either a call to be made or internet to be browsed. Once a call comes in, the internet gets disconnected. But here it has overcome the disadvantage and now both phone calls and internet can be used simultaneously.