OAuth 2.0 is a set of specifications that allow developers to easily delegate the authentication and authorization of their users to someone else. While the specifications don’t specifically cover authentication, in practice this is a core piece of OAuth, so we will cover it in depth (because that’s how we roll).
What does that mean, really? It means that your application sends the user over to an OAuth server, the user logs in, and then the user is sent back to your application. However, there are a couple of different twists and goals of this process. Let’s cover those next