PPPoE (Point to Point Protocol) over Ethernet, as the name implies, means that we run PPP on top of Ethernet. This is often used by Internet Service Providers who offer DSL / Cable Internet access. PPP was traditionally used in dial-up networking and offers authentication, which ISPs used to authenticate their users. Computers and routers nowadays use Ethernet, by running PPP on top of Ethernet, ISPs can still use PPP for authentication.