Identification and authentication are two terms that describe the initial phases of the process of allowing access to a system. The terms are often used synonymously, but authentication is typically a more involved process than identification. Identification is what happens when you profess to have a certain identity in the system, while authentication is what happens when the system determines that you are who you claim to be. Both processes are usually used in tandem, with identification taking place before authorization, but they can stand alone, depending on the nuances of the system.
A login system uses both identification and authentication.
