On the installation day an engineer will fit a new faceplate to your master telephone socket. The faceplate has two sockets, one for your new Vodafone fibre broadband modem and another for phone services (telephone, fax machine, Sky box etc.).
The fibre broadband service will only work on a phone socket that has been fitted with the fibre broadband faceplate. You will not be able to connect to the Internet if you plug your Vodafone Fibre modem in to any socket other than the new master socket.