An acronym for Point-to-Point Protocol over Ethernet, PPPoE allows multiple users to connect to a network using the same server. This connection can happen on a modem, router, or computer operating system. A PPPoE connection typically happens with an internet service provider (ISP), though individual users can also configure their computers with a PPPoE connection.
Point-to-Point Protocol (PPP) originated with dial-up internet connections (through phone lines). PPP network connections only allowed one computer to use the internet through a server. When households began using multiple devices on one network, PPPoE became important. PPP offered message encryption features, which PPPoE also has.
PPPoE is a two-step process for confirming an internet session. The first step is commonly known as the discovery stage, in which the Point-to-Point Protocol authorizes the user so that the ISP knows that they can have a legitimate connection. The user’s media access control (MAC) address in their network is verified. After the user is authorized, the second step - known as the session stage - begins. The user and internet now have a session ID, along with a few other fields that need to be filled with information about the session. This includes which Internet Protocol version (probably IPv4 or IPv6) the session will use.